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tudies on Insects Affecting the Fruit of 
the Apple 

With Particular Reference to the Characteristics 
of the Resulting Scars 



A THESIS 

PRESENTED Tu THE FACULTY OF THE GRADUATE SCHOOL OF 

CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOvSOPHY 



BY 

HARRY HAZELTON KNIGHT 



Published as Bulletin 410 

Cornell University Agricultural Bxperiment Station, May 1922. 



Studies on Insects Affecting the Fruit of 

the Apple 

With Particular Reference to the Characteristics 
of the Resuhing Scars 



A THESIS 

PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL OF 

CORNELL UNIVERSITY FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



HARRY HAZELTON KNIGHT 



Published as Bulletin 410 
Cornell Universit}- Agricultural Experiment Station, May 1922. 



ACoKCo 



n. 



Bm **f«^a.v.^\;i. 



CONTENTS 

PAGE 

Insects studied ..." 450 

Methods of study 450 

Growth of fruit in relation to time of injury a factor in the type of scar developed . . 451 

Nature of injuries caused by different species 453 

Hemiptera 453 

The light apple redbug (Lygidea mendax Reuter) 453 

Redbug injury combined with injury by the rosy aphid 456 

Varieties of apples injured by Lygidea tnendax 456 

The dark apple redbug {Heterocordylus malinus Reuter) 456 

The colon apple leaf bug {Paracalocoris hawleyi pallidulus McAfee) 457 

The clouded apple leaf bug ( Neurocolpus nubilus Say) 457 

The rosy apple aphid {Aphis sorbi Kaltenbach) 458 

The apple leaf aphid {Aphis pomi De Geer) 459 

The San Jose scale {Aspidiotus perniciosiis Comstock) 460 

The oyster-shell scale {Lepidosaphes ulmi Linnaeus) 461 

The scurfy scale ( Chionaspis furfura Fitch) 462 

Lepidoptera 462 

The codling moth {Carpocapsa pomonella Linnaeus) 463 

The lesser apple worm {Enarmonia prunivora Walsh) 467 

The fruit-tree leaf roller {Archips argyrospila Walker) 468 

The oblique-banded leaf roller {Archips rosaceana Harris) 470 

The green fruit worm ( Xylina antennata Walker) 471 

The green fruit worm ( Xylina laticinerea Grote) 473 

The red fruit worm {Rhynchagrotis placida Grote) 473 

The white-marked tussock moth {Hemerocampa leucostigma Smith and Abbot) 474 

The palmer worm ( Ypsolophus ligulellus Hubner) 476 

The bud moth {Tmetocera ocellana Schififermiiller) 477 

The red-banded leaf roller {Eulia velutinana Walker) 478 

The pistol case-bearer {Coleophora malivorella Riley) 479 

The cigar case-bearer ( Coleophora fletcherella Fernald) 480 

The fall webworm {Hyphantria texlor Harris) 481 

The apple serpentine miner {Marmara pomonella Busck) 481 

Coleoptera 482 

The plum curculio {Conotrachelus nenuphar Herbst) 482 

The apple curculio {A nthonomus quadrigibhiis vSay) 485 

The rose chafer {Macrodactylus siibspinosus Fabricius) 486 

Diptera : 487 

The apple maggot {Rhagoletis pomonella Walsh) 488 

Hymenoptera 489 

The apple-seed chalcis {Syntomaspis druparum Boheman) 490 

The dock false- worm {Ametastegia glabrata Fallen) 490 

Injuries to the fruit of the apple by agencies other than insects 491 

Warting of scars ., 491 

Mechanical injuries 491 

Experiments in producing scars by pin punctures 492 

Cracking fruit 492 

Lime-sulfur spray injury 493 

Sun-scald 493 

Scars produced by frost injury 494 

Hailstone injury , 495 

Apple scab 496 

Stippen 496 

Acknowledgments 496 

Bibliography \ 497 



447 



STUDIES ON INSECTS AFFECTING THE FRUIT OF THE 

APPLE, WITH PARTICULAR REFERENCE TO THE 

CHARACTERISTICS OF THE RESULTING SCARS ^ 

Harry Hazelton Knight 

During the season of 1914 the writer began an extensive series of 
observations on the production and development of scars induced by the 
various insects attacking the apple. The ultimate aim of this work was to 
make it possible to determine from the characters of the scars on the apples 
at picking time what insects had caused them, so that the ofchardist might 
deal more intelligently with these obscure foes. The writer was able to 
carry on this work under most favorable circumstances in cooperation 
with the Genesee County Fruit Growers' Association, spending all his time 
during four growing seasons in orchards throughout Genesee County. 
Extensive data were obtained on the scars and blemishes caused by all 
of the well-known injurious insects affecting the fruit of the apple, and 
detailed observations and photographs were made of the work of several 
species that are scarcely to be recognized from the scars they produce. 
New and little-known types of scars were studied, particularly those 
caused by the apple redbugs Lygidca vicndax and Hctcrocordylus malinus. 
The scars caused by these bugs were found to develop differently accord- 
ing to the variety of apple affected and the time of puncture with refer- 
ence to the growth of the fruit. Several species of lepidopterous larvae 
are known to injure the fruit of the apple, and comparative studies were 
made of fifteen different species and photographs were obtained showing 
the chief characteristics of their work and the resulting scars. In all, 
thirty species of insects, representing five orders, were found attacking 
the fruit of the apple in western New York, and comparative studies show 
that with sufficient observation and experience a large profxirtion of all 
the blemishes and scars found on apples at picking time may l)e correctly 
referred to the insects causing them. Comparative studies with an exten- 
sive series of photographs were made of the scars and blemishes caused 
by agencies other than insects, particularly by spray injury, mechanical 
injuries, apple scab, frost, and hailstones. 



t Also presented to the Faculty of the Graduate School of Cornell University, June, 1920, as a thesis 
in partial fulfillment of the requirements for the degree of doctor of philosophy. 



449 



450 Bulletin 410 

INSECTS STUDIED 
The species of insects studied were the following: 

Hemiptera : 

1. The light apple redlnig (Lygidca mcndax Renter) 

2. The dark apple redbug {Hctcrocordylus maUnus Renter) 

3. The colon apple leaf bug {Paracalocoris haivlcyi pallididus 

McAtee) 

4. The clouded apple leaf bug (Ncurocolpiis mthiliis Say) 

5. The rosy apple aphid (Aphis sorbi Kaltenbach) 

6. The apple leaf aphid (Aphis pomi De Geer) 

7. The San Jose scale (Aspidiotus pcrniciosus Comstock) 

8. The oyster-shell scale (Lcpidosaphcs iilmi Linnaeus) 

9. The scurfy scale (Chionaspis furfur a Fitch) 

Lepidoptera : 

1. The codling moth (Carpocapsa pomoncUa Linnaeus) 

2. The lesser apple worm (Enarmonia prunivora- Walsh) 

3. The fruit-tree leaf roller (Archips argyrospila Walker) 

4. The oblique-banded leaf roller (Archips rosaccana Harris) 

5. The green fruit worm (Xylino antcnnata Walker) 

6. The green fruit worm (Xylina laticincrca Grote) 

7. The red fruit worm (Rhynclwqrohis placido Grote) 

8. The white-marked tussock moth (Hcmcrocampa leiicostigma Smith 

and Abbot) 

9. The palmer worm (Ypsolophus liyulclliis Hiilmer) 
10. The bud moth (Tmctoccra occUmia Schififermiiller) 
ri. The red-banded leaf roller (Eidia vchitinana Walker) 

12. The pistol case-bearer (Colcophora nialivorcUa Riley) 

13. The cigar case-bearer (Colcophora fictcJicrcUa Fernald) 

14. The fall webworm (Hyphantria tcxtor Harris) 

15. The apple serpentine miner (Marmara pomoncUa Busck) 

Coleoptera : 

1. The plum citrculio (Conoltachclus nenuphar Herbst) 

2. The apple cuvculio {Anthonoinus-quadrigibbiis Say) 

3. The rose chafer (Macrodactylus subspijiosits Fabricius) ■ 

Diptera : 

I. The apple maggot (Rhagolctis pomoncUa Walsh) 

Hymenoptera : 

1. The apple-seed chalcis (Syntomaspis dntparuni Boheman) 

2. The dock false-worm (Ainctastcgia glabra ta Fallen) 

METHODS OF STUDY 

In conducting the observations, large shipping tags were used to keep 
track of the injured apples. On these tags were written all data regard- 
ing the time of injury, and subsequently additional notes were added con- 
cerning the development of the scars. Large numbers of apples were 
tagged for each species of insect found at work in the various orchards, 



Insects Affecting the Fruit of the Apple 451 

and at short intervals throughout the growing period specimens were 
picked and photographed so that a record might be kept of each kind of 
injury in its various stages of development. Where it was desirable to 
cage insects on the limb with the fruit — as, for example, to find what 
injuries a particular larva, nymph, or adult might produce, or to prevent 
other insects from adding scars to the experiment — a coarsely woven 
fabric called tarlatan was used for inclosing the limb and ' fruit. This 
material allows sunlight and rain to pass through readily, thus permitting 
normal growth, whereas the use of cheesecloth or other heavy and coarsely 
woven material was found to be detrimental to growth, causing the leaves 
to drop and the fruit to remain stunted. 

For convenience in carrying out the photographic work, a small labora- 
tory, equipped with dark room and skylight, was erected in one of the 
orchards (Plate III). Here the work was carried out to better advantage 
than would have been possible with the camera at some distant point. 
This laboratory consisted of a frame structure, 10 by 12 feet in area by 
9, feet in height at the ridgepole, with sides screened and the roof cov- 
ered with a light canvas except for one-half of the south exposure, which 
was fitted with glass to form a skylight. The dark room, 5 by 5 feet in 
area by 6 feet in height, occupied the rear corner opposite the operating 
table and skylight, and was made lightproof by several thicknesses of lar 
paper tacked over a framework containing a door with a passageway. A 
thick, dark ruby glass, set in one side as a window, furnished all the neces- 
sary lighting, thus completing a very simple but effective dark room. 

GROWTH OF FRUIT IN RELATION TO TIME OF INJURY A FACTOR IN 
THE TYPE OF SCAR DEVELOPED 

The amount of injury in an orchard as measured by the proportion of 
injured fruits at picking time, and the types of scars produced, depend on 
several factors. When there is a heavy set of fruit, it is always the weak 
and injured fruits that drop first; the fruits that get a strong start and 
are free from injury are the ones that survive. In years when there is a 
heavy set, therefore, the redbugs and the leaf-roller larvae may actually 
help to thin the fruit without leaving a noticeable proportion of scarred 
fruits, since it is the injured apples that drop in the thinning process. 
If the season is favorable to very rapid growth following the blooming 
period, a larger proportion of injured fruits will recover and grow to 
maturity than in a year when growth is slow following the bloom. In a 
year when there is a light set of fruit and the period of growth is favor- 
able to rapid development, the conditions are right to produce the largest 
proportion of scarred fruit at picking time, since by forced growth many 



452 Bulletin 410 

weak and injured fruits are able to develop that otherwise would have 
dropped. Any condition that tends to force the growth of the tree will 
enable more of the injured and weak fruits to grow and recover. The 
writer soon learned to thin the fruit on the limbs on which he was tagging 
apples that were being injured by an insect ; if this were not done, it was 
found that about 95 per cent of the fruits tagged would drop and the 
experiment would be lost. 

Certain varieties of apples are more subject to fatal injury than are 
others. Apples that grow to a large size, such as the Twenty Ounce and 
die pippin varieties, develop rapidly and can withstand or recover from 
wounds such as would cause a slow-growing variety to drop. The 
Northern Spy is a variety that develops slowly following the set of the 
fruit, and thus the injured fruits are more likely to drop. Strong vitality 
in the development of the fruit is particularly noticeable in pippin and 
Twenty Ounce apples injured by larvae of the fruit-tree leaf roller. 
These fruits may have part of the core eaten out and still develop to 
maturity, showing the remains of the core tissue at the bottom of the 
wound. 

It was found that different varieties of apples would develop different 
kinds of scars when attacked by the same insect, this being particularly 
true in the case of the apple redbugs. Fruits that are punctured when 
very small and growing rapidly develop a different type of scar from that 
produced on apples that are attacked at a more mature stage. If the core 
of the young apple is punctured by feeding redbugs, the flesh of the fruit 
never grows back at the point of puncture and a deep pit results in the 
mature apple (Plate IV, 4). Later, when the fruit is of such size that the 
insect is unable to reach the core, the flesh will develop beneath the point 
of puncture and tend to reduce the depth of the pit. When the growth 
is sufficiently rapid, the pit may disappear entirely and a spreading russet 
scar take its place. After the apples have reached more than a cjuarter 
of an inch in diameter, growth is very rapid, and the punctures made by 
redbugs cause a splitting of the fruit skin which continues to enlarge with 
the growth of the apple until broad russet scars result (Plates IV, 3, VII, 
20 and 21, and VIII, 22). Wounds made later in the season do not heal 
so readily as do those made while the fruit is expanding by rapid growth 
early in the season. Wounds made after the middle of July never heal 
with a clean scar, but become covered with a thick, corky layer formed 
by the dead and dried cells of the fruit. In the case of these later injuries, 
which are usually produced by the tussock moth or the plum curculio, the 
maturing date of the variety has much to do with the healing of the 
wound. Early-maturing varieties do not heal the wounds made after 
growth is nearly completed, and in many cases brown rot results. 



Insects Affecting the Fruit of the Apple 453 

NATURE OF INJURIES CAUSED BY DIFFERENT SPECIES 
HEMIPTERA 

The order Hemiptera includes all of the true bugs, and in the present 
study all the hemipterous insects discussed come within the families 
Miridae, Aphididae, and Coccidae. The Hemiptera develop by gradual 
metamorphosis, and thus the nymphs, in their feeding habits and activities, 
are similar to the adults. Both nymph and adult puncture the fruit by 
means of a long proboscis and suck juices from the tender tissue. In 
most cases the injuries by the adult are little different from the work of 
the nymphs except in point of time, and any difference that may be noted 
is due to the difference in the stage of growth of the fruit as related to 
the time when the puncture is made. 

TJic light apple rcdbitg 
{Lygidea mcndax Renter) 

The nymphs of Lygidea mendax begin hatching just as the blossom 
buds separate at the tips, and most of them have entered the second instar 
by the time the blossom buds show pink and are ready for the first scab 
spray. The nymphs are in the third instar while the trees are in bloom, 
and most of them have entered the fourth stage by the time the petals 
have fallen. It is during the fourth and fifth instars that the greatest 
amount of damage is done, or from the time when the petals fall to the 
time when the young apples are one-half inch in diameter. In 191 4, which 
was a normal growing season, the adults of Lygidea mcndax were matur- 
ing rapidly by June 18, and practically all were mature by June 22. The 
adults feed on the fruits extensively for a week or more, and then, as the 
fruits get larger and become tough, they begin feeding more on the tender 
shoots that develop. 

When the redbug UA-mphs first begin feeding on the young fruit, the 
tissue of the core is usually punctured. In a short time, however, the 
fruit has increased in size to such an extent that the insect's proboscis is 
no longer able to reach the core tissue. Redbug punctures that penetrate 
the core develop a very different type of scar from those made at a later 
period. When the core tissue is punctured, the fleshy part of the apple 
grows up around the point of puncture, leaving a deep pit where the 
injury occurred ; this is shown in Plate V, 7, a photoghraph made ten 
weeks after the fruit was punctured. Such apples invariably develop deep- 
sunken pits, as shown in the mature Northern Spy apples in Plates V, 8, 
and VI, 12. Of the varieties observed by the writer, the Northern Spy 
is the slowest in developing size in the fruit, and thus a higher proportion 
of deeply pitted apples is found in that variety. The Rhode Island Green- 



454 Bulletin 410 

ing and the Baldwin apples develop more rapidly following the set of the 
fruit, and hence the time is shorter during which the insects may reach 
the core and produce the deep wounds ; this results in a smaller proportion 
of deeply pitted apples (Plate V, 9) and a greater number of the russet- 
scar type. 

The irregular russet scars that have been so little understood are 
developed from punctures made just after the apple has become too large 
for the insect to reach the core with its beak and while the fruit is growing 
rapidly. In Plate IV, i, Rhode Island Greening fruits are shown with 
nymph and adult redbugs, at a time when the core may no longer be 
reached (June 18) but at a period when the feeding punctures will pro- 
duce ultimately the peculiar russet scars shown in Plates IV, 3, VII, 20 
and 21, and VIII, 22. These young apples (Plate IV, i) show injuries 
produced by feeding punctures made on June 10 and 11. The smaller 
apple shows in two or three places that the core was penetrated when the 
bug inserted its proboscis, while the larger one had passed that stage 
before the injury was made. When the fruit is first punctured the sap 
runs out freely, this being followed by the development of a thick gelat- 
inous covering to the wound the edges of which turn white after a few 
hours. In two or three days the wound becomes rusty brown, and if the 
apple is growing rapidly the skin splits and thus enlarges the wound (Plate 
V, 5 and 6). It is the late injuries, made when the apple is growing most 
rapidly, that spread into the broad, shallow, russet scars. In many cases, 
even when punctured early the apple recovers so completely that no depres- 
sions result and only the broad, irregular russet scars are seen (Plates IV, 
3, VI, 13, and VIII, 22 and 23). 

Northern Spy apples punctured by the feeding bugs between June 12 
and 14 were photographed when examined on July 8, at which time the 
characteristic splitting of the skin was well developed about the wounds 
(Plate IV, 2). The condition of the apple shown in this figure is almost 
an exact duplication of the condition on July 8 of the Northern Spy apple 
shown in Plate IV, 3. The mature apple shows how the scars have run 
together and healed to such an extent that no depressions have been 
formed. Baldwin apples punctured between June 10 and 18 were exam- 
ined on July 3, at which time they showed the characteristic splitting of 
the skin about each of the punctures. This condition is well illustrated in 
Plate V, 6. It is at this age that the scars very much resemble certain 
developments of apple scab (Plate VII, 18). In Plate VI, 14, is shown 
a Rhode Island Greening apple (photographed on July 7) in which the 
scars are just developing but will soon spread and take on a russet 
character. Red Astrachan apples, being an early variety, develop more 



Insects Affecting the Fruit of the Apple 455 

rapidly than do standards, and thus the scars on that fruit will have on a 
given date a more advanced character than on the Baldwin^ Rhode Island 
Greening, and Roxbury apples. 

Very soon after the adult bugs emerge, or by June 25 to 27, the apples 
have attained such size and the growth is so gradual that the punctures 
made by the bugs do not split and enlarge as do the punctures made 
earlier. In Plate VI, 10 and I'l, is shown the effect of late feeding of 
adult bugs, which may result in mere dimples or in tiny russet spots, 
depending much on the variety affected. The spots on the apple shown 
in Plate VI, 10, resemble very closely the dimples caused by the deposition 
of eggs by the apple maggot fly ; but if they were the work of the latter, 
a cross section of the puncture would show either where the &gg was 
placed or the winding trail of the maggot leading from it. The work of 
the apple-seed chalcis (Syntoniaspis druparum) may resemble the work 
of apple maggot flies or very late-feeding punctures of redbugs, but in 
injury by the chalcis the larvae of the fly may be found in the seeds or a 
careful section will show the slender, straight trail of the ovipositor lead- 
ing to the seeds (Plate XXXIV, 142). 

Roxbury and Golden Russet apples are subject to injury by redbugs. 
The pitted and russet types of injury resulting on Roxburys are shown 
in Plate VII, 19, while the work on Golden Russets (July 13) is shown in 
Plate VI, 15. The early injuries produce deep pits, while the latest 
punctures cause russet scars that may frequently be hard to distinguish 
from the normal appearance of those varieties. In Plate VIII, 23, is shown 
a mature Roxbury apple injured by fifth-stage nymphs between June 15 
and June 18, on which the russet scars healed so evenly with the normal 
surface that the apple would probal)ly have passed inspection as Grade A 
fruit. The Baldwin apple shown in Plate VIII, 22, is perfectly shaped, 
but it has the characteristic russet scars developed from the late-feeding 
punctures of redbugs. In Plate VII, 21, is shown a mature but stunted 
Baldwin apple, which recovered from injuries of the feeding bugs although 
the adjoining fruit was so badly punctured that it died and shriveled up 
but still clung to the tree. Scars from late feeding were observed on 
Bough apples, these being very similar to scars found on Champlain and 
other early varieties. Russet scars caused by redbug punctures on Detroit 
Red apples were found to be very conspicuous on the dark skin of that 
variety. The same type of scars is shown on St. Lawrence apples (Plate 
VI, 13), and in this case the original rough scars, noted in July, changed 
to a smooth, Ijrassy surface on the mature fruit. 

The appearance of redbug scars differs according to the variety and is 
most interesting in some of the unnamed apples. In Plate VII, 20, are 



4s6 Bulletin 410 

shown the very conspicuous russet scars produced on an unnamed variety 
having a light-colored transparent skin. Certain of the slow-growing 
natural fruits do not split about the wound and develop the enlarged scars 
that occur in varieties having more rapid growth. Typical stages of red- 
bug work are seen on the young natural fruits shown in Plate VI, 16 
(photographed on July 6). Lygidca mcndax was found breeding also on 
quince, where the bugs feed on the fruits and produce typical scars (Plate 
IX, 27) which ,in some cases might be mistaken for the work of the quince 
curculio. 

Numerous fruits were tagged in the process of following the work of 
redbugs on the several varieties of apples, and in a few cases photographs 
were made of the young injured apple on the tree and again when the 
fruit was mature. 

Redbug injury combined with injury by the rosy aphid 

Under certain conditions the rosy aphid (Aphis sorbi) may develop and 
feed on apples injured by redbugs. When this occurs, the scars started 
by the redbugs are much enlarged and otherwise changed by the aphids 
(Plate VIII, 24). The work of the rosy aphid on apples tends to stunt 
the fruit as well as to cause it to become badly misshapen. The redbug 
punctures affected by aphids c|evelop a wound having an ugly white frothy 
scab, which may eventually heal and produce a badly gnarled fruit. In 
Plate VIII, 25, are shown two mature Rhode Island Creening apples 
which on June 25 appeared exactly as did the injured fruits shown in 
Plate VIII, 24. 

Varieties of apples injured by Lygidea mendax 

The varieties of apples most affected by Lygidea mendax in Genesee 
County are here given in the order of greatest injury suffered: Rhode 
Island Greening, Northern Spy, Baldwin, Roxbury, Tolman, Tompkins 
King, Maiden Blush, Twenty Ounce, Esopus, Fall Pippin. 

The dark apple redbug 
{Hctcrocordylus malinus Renter) 
The dark apple redbug (Heterocordylus malinus) develops from seven 
to ten days earlier than does Lygidea mendax, and this makes considerable 
difference in its ability to injure apples. The nymphs hatch with the 
unfolding of the leaves, and feed on the tender foliage and to a slight 
extent on the fruit before reaching maturity. In a few cases the adult 
bugs have been observed to feed on the fruit, but all fruits so attacked 
dropped within a short time. It is apparent that in the case of most 



Insects Affecting the Fruit of the Apple 457 

varieties of apples the insects have practically finished feedinj^ before the 
fruit is large enough to withstand the injuries of the bugs and remain on 
the trees; therefore, most of the injured fruits drop, and very few reach 
maturity with their scars. 

In trying to get definite data on the work of this species, the writer 
carried out in 191 5 no less than forty experiments, each of which con- 
sisted of isolating two fourth- or fifth-stage nymphs on an apple branch 
which was blooming and setting fruit. This was accomplished by using, 
as cages, bags made of tarlatan, which were drawn up around the limb 
and firmly tied. The nymphs invariably preferred to feed on the tender 
fohage instead of on the fruit. The few fruits that were punctured by 
the bugs did not survive the June drop and thus were lost. 

The adults of this species (Plate IX, 26) are mature and have begun 
to lay eggs by the time the fruit is large, enough to be injured, and thus 
their opportunity for doing harm is not so great as is that of Lygidca 
mcndax. Redbug injury on Twenty Ounce apples which developed on a 
tree infested by Hctcrocordyhis malinus and which the writer believes to 
be the work of that species, is shown in Plate IX, 28. The Twenty Ounce 
and pippin apples are, by the nature of their rapid development, the most 
likely to attain the size necessary to withstand the feeding punctures of 
the bugs and thus to develop mature scars from this species. It appears 
certain that in western New York the work of Hctcrocordyhis malinus 
in producing knotty fruit is very limited or entirely absent on the standard 
varieties of apples. 

The colon apple leaf hug 
(Paracalocoris hawlcyi pallidjthis McAtee) 
One of the leaf bugs which was frequently found breeding on apple was 
Paracalocoris hazulcyi palliduliis, a form that usually develops on the 
tender shoots about the roots and the trunk of the tree. When abundant 
it may move to the branches above and occasionally feed on the young 
fruit. A few such fruits were tagged, but no mature apples were obtained 
showing scars caused by this species. 

The clouded apple leaf bug 
(Neurocolpus nubiltis Say) 
Another leaf bug which has been reported as feeding on apple in 
Canada, and which the writer found breeding on apple in Genesee County, 
is Neurocolpus nubilus Say. This species also was found to prefer the 
tender shoots on the apple tree, and in this case the bugs were not observed 
feeding on the fruit. 



458 Bulletin 410 

The rosy apple aphid 
(ApJiis sorbi Kaltenbach) 

The rosy aphid, when present on the apple tree, makes its presence 
known just as soon as the young fruits are set, and immediately develops 
so rapidly and in such numbers that the young fruit stems and adjoining 
leaves soon become pink with the crowded aphids. By the time the young 
fruits are one-half inch in diameter, or by the end of June, this sjjecies of 
aphid migrates from the apple tree, but not before it has done considerable 
damage. The rosy aphid prefers to develop on the lower limbs and on 
the inside or shady parts of the tree, but in years when it is alnmdant and 
the season is favorable it may spread to all parts of the tree and do 
immense damage unless control measures are taken by spraying at the 
right time. The writer found this aphid present each season in limited 
areas, particularly on Rhode Island Greciiiug trees and in orchards where 
ihe trees were crowded and not properly j^runed. 

Where the rosy aphid has developed and has sapped the stems of the 
young apples, the fruits never become thinned out during the June drop. 
All infested fruits remain on the tree, forming clusters where there should 
be only one apple growing. A typical group of young fruits just recently 
abandoned by the rosy aphid is shown in Plate IX, 29. The cast-off skins 
of the developing aphids are shown on the leaves, and each fruit that set 
following the bloom still clings and continues to develop very slowly in its 
gnarled and injured form. This species of aphid does not remain long 
on the fruit, for by June 25 the winged forms were rapidly developing 
and leaving the apple tree in favor of their alternate, or summer, host 
plant. It appears that the feeding aphids have a tendency to harden the 
stems of the young fruit, causing each one so affected to cling and produce 
the crowded and undersized condition of fruits so characteristic of trees 
where aphids have been at work. Few if any seeds are present in the 
apples thus affected, and all retain a gnarled and malformed shape, par- 
ticularly a puckered appearance at the base and at the calyx end (Plate 
XI, 32). In Plate X, 30, is shown a cluster of six young apples, photo- 
graphed on the tree on July 4, which were identical in appearance on 
June 24 to those in the cluster shown in Plate IX, 29. The same six fruits 
(Plate X, 30) are shown in their natural size at picking time (Septeml)er 
25) in Plate X, 31. The fruits still show the' heavy coating of spray 
material to which the tree was subjected during the first week in August. 
. All varieties of apples are infested in years when the season is favorable 
to the increase of aphids, but of the standard varieties the Rhode Island 
Greening and the Baldwin apples are the most frequently affected. It was 
observed that Baldwin apples may be infested only very slightly by the 



Insects Affecting the Fruit of the Apple 459 

aphid, yet each apple will remain on the tree until picking- time, being 
about one-third the normal size for that variety and showing the char- 
acteristic puckering elYect at the calyx end. Systematic thinning of the 
young fruits helps somewhat to increase the size of apples thus affected, 
but still the result is far from satisfactory to the grower. The most 
distinctive malformation caused to the apple by the rosy aphid is the 
puckering at the calyx end, which is very often accompanied by puckering 
at the base also. In Plate XI, 32. are shown three pippin apples (Septem- 
ber 9) which were puckered chiefly at the base, this probably being due to 
the fact that in this variety the young apples developed and increased in 
size so rapidly that the aphids did not work beyond the broad base as 
they do on the small fruits. Heavily infested fruits usually develop a 
characteristic riljbing and warting of the surface, a condition produced 
only by clusters of these small insects. Idie uneven surface and pucker- 
ing of the fruit is due to the fact that where the cells are punctured by 
the sucking aphids, little growth takes place, .while the surface between 
punctures tends to grow ; hence the warting. Red Astrachan apples 
affected by the rosy aphid are stunted similarly to other varieties, and in 
addition they are found to ripen sooner than other fruits on the tree. A 
fruit cluster of this variety which was infested by aphids in June was 
found to be ripe and cracking open by July 13. 

On May 28, 191 5, a killing frost occurred in western New York, 
destroying all the fruit in many of the orchards. A curious phenomenon 
was noted in those orchards where the fruit was killed, namely, that the 
fruit clusters infested by the rosy aphid did not wither and .fall as did all 
other fruits. The apples in the aphid-infested clusters were found to be 
without seeds and were very much stunted and malformed. These aphid- 
infested and frosted fruit clusters were found to cling to the tree through- 
out the summer and even until picking time. 

TJic apple leaf aphid 
(Aphis poiiii De Geer) 
The apple leaf aphid breeds on the tree throughout the season but 
becomes most abundant dvu-ing July, the period immediately following the 
disappearance of the rosy aphid from the apple tree. The injuries it 
produces are usually made in a slightly different manner from those of 
the rosy aphid. ApJiis poiiii is always most al)undant on the new succulent 
growth, and particularly on young trees that are growing rapidly. In 
years when the season is favoralile for ai>hid development, even the large 
and well-pruned trees of standard varieties become seriously affected. 
The damage caused by this species is often not so much in stunting or 



460 Bulletin 410 

mal forming the fruit as in the production in vast quantities of honeydew 
which covers the fruit. A black fungus soon develops on this honeydew 
excretion, covering the leaves and the fruit to such an extent that the 
latter is rendered unsalable from its appearance alone (Plate XI, 34). 
This aphid usually works only on the fruit stems and the leaves, checking 
the growth of the apples to such an extent that by picking time they are 
only half or one-third the size of normal fruit. But in years of greatest 
abundance the aphids may even cover the whole apple and produce the 
puckered fruit so characteristic of the work of Aphis sorbi. The fruit 
is usually an inch or more in diameter by the time the leaf aphids I)egin to 
cover the tree. By that time the June drop has caused a thinning of the 
fruit, and the apples that remain during July are expected to develop and 
reach maturity. 

Because of its later development, this species does not normally produce 
the clustering of fruits to such an extent as is found in the case of 
A. sorbi. In Plate XI, 33, is shown a cluster of Baldwin apples which 
were infested by the rosy aphid until June 25 and then by A. poini, which 
followed immediately and persisted until July 20. The puckering of the 
fruit was caused almost entirely by the rosy aphid, while the black and 
smutty appearance produced by honeydew and fungus is the natural 
result always following in the wake of A. pomi. Very frequently young 
and thrifty apple trees may produce fruit of normal size, yet the aphids 
developing almost exclusively on the leaves will excrete sufficient honey- 
dew to cover the apples and make them unsalable from their appearance. 
One can invariably detect the work or the previous infestation of A. pomi 
from the fruits alone, since the black or smutty appearance caused by the 
fungus remains for a long time. 

The San Jose scale 

(Aspidiotus pcniiciosits Comstock) 

At least four species of scale insect's may occur on the apple in New 
York, but the one most frequently seen on the fruit is the San Jose, or 
pernicious, scale. If this scale is at all present on the tree, it is almost sure 
to make its appearance on the fruit before the apples reach maturity. One 
scale-infested orchard that the writer observed was always treated with 
the dormant lime-sulfur spray, but apparently there were always a few' 
",pots left untouched by the solution since the insects invariably developed 
on several trees and a certain percentage of the fruit always showed the 
scale spots. In the fruits observed and photographed, the young insects 
began settling on the apples during July. They were few in number at 
this time, but before the fruit was picked these first scales had matured 



Insects Affecting the Fruit of the Apple 461 

and had produced numerous young which covered the stem and calyx 
ends, and frequently the sides of the apple as well (Plate XII, 35 and 36). 
The lenticels in the skin of the apple show as minute white dots, while 
the young scales may invariably be distinguished by the appearance of a 
still smaller dark speck in the centers of the spots formed by them. 

On badly infested trees the stem and calyx ends of the apples are 
usually found to be plastered with numerous small black scales which 
cover the half-grown insects and form a grayish, roughened, scurfy mass 
on the skin of the fruit (Plate XII, 35). The largest scales, covering the 
full-grown females, are nearly circular in outline, grayish in color, and 
about the size of a pinhead ; while the smaller, half-grown scales are 
blackish, with a central gray dot surrounded by a black depressed ring 
which in turn is surrounded by a grayish ring. One can usually distin- 
guish the San Jose scale from other closely related species by the form 
of the young scale, the raised cone point at the center of the scale, and 
the surrounding black depressed ring. 

When infested apples mature on the tree, a red color develops around 
each scale or cluster of scales which gives a very characteristic and well- 
known scale-infested appearance to the fruit (Plate XII, 36). In a 
favorable season, such as 1914, when rains occur during August and 
produce a late scab-infection period, some of the early-maturing apples, 
particularly Maiden Blush, may develop a color about the tiny seal) infec- 
tions, producing an effect not greatly different from that of scale (Plate 
XII, 37). In the writer's experience a good many growers have noted 
this late scab infection with considerable concern, thinking it must be the 
San Jose scale. A person familiar with scale could scarcely make this 
mistake, however, since a close examination shows the absence of any 
scale and in its stead a tiny black six>t surrounded by a pale, scurfy-like 
ring caused by the scab fungus forcing up the thin, transparent layers of 
epidermis, beyond which color may develop in the skin of the fruit. Late 
scab infection is shown in Plate XLII, 181, on a Rhode Island Greening, 
which is typical of the dark green varieties in that no color developed 
about the points of scab infection. 

The oystcr-shcll scale 

(Lcpidosaphcs iihni Linnaeus) 

Another scale which is frequently found on apple trees throughout New 
York State but is not of prime importance is the oyster-shell scale. This 
species may infest trees to such an extent that limbs may be killed, but 
since it has only one brood in New York there is scarcely any opportunity 
for the young to settle on the fruit. The tiny young scales are hatched 



46^ Bulletin 410 

and complete their active period of moving over the tree before the apples 
set, and therefore in the northern locahties there is httle opportunity for 
infesting the fruit. Apples showing the oyster-shell scale developed on 
the fruit are on record, but these fruits evidently all came from more 
southern localities where two broods of this scale develop in one growing 
season. 

The scurfy scale 

{Cliioiiaspis furfiira Fitch) 

The scurfy scale is recorded from several localities in New York, but 
the writer failed to find it infesting the apple in the western part of the 
State. Slingerland and Crosby record two broods of this scale at Ithaca, 
New York, and the writer has seen the scales on the fruit of pear from 
the same locality, which would indicate that two broods had developed. 
In localities where two generations develop, the second l^rood might be 
expected to i)roduce some scale on the fruit in those orchards where it 
occurs on api>le trees. This species of scale is easily distinguished by the 
broad, grayish white, pear-shaped female scales, with two minute cast 
skins clinging to the smaller end of the broad, thin, whitish part which 
forms the scale proper. 

LEPIDOPTERA 

In the Lepidoptera only the immature, or larval, stage of the insect is 
able to do damage to fruit. The adults have sucking mouth parts suited 
for taking up nectar or other substances in liquid form, and thus they 
rarely have opportunity to injure fruit. Ripe peaches are sometimes 
ruined in the_Central States by depredations of the migrating cotton moths 
(Alabama argiUacea), which sometimes congregate in large numbers to 
sip the sweet juice of ripened peaches. The writer has seen army-worm 
moths (Cirphis unipuncta) feed on the juices of very ripe Bough apples 
on the tree. But aside from such rare occurrences, it may be stated that 
the adult insects of this order do not cause injury to fruit. The lepi- 
dopterous larva is provided with mandibles by means of which it cuts and 
prepares its food for entry into the alimentary tract ; therefore, although 
the adult is a sucking insect, the larval stage must be placed in a group 
commonly designated, for convenience, as having biting or chewing mouth 
parts. 

Lepidopterous larvae may feed externally or internally on the apple. 
As representatives of internal feeders, the codling moth and the lesser 
apple worm furnish the most conspicuous examples. The internal feeding 
results in wounds that never heal perfectly, usually ending in brown rot, 
premature ripening, and falling of the fruit before picking time. Wounds 



Insects Affecting the Fruit of the Apple 463 

made by the external feeders — and these species are the most numer- 
ous — will often heal over, producing a characteristic scar, provided the 
injury occurs prior to mid-July while the apple is growing rapidly. 
Wounds produced later than the middle of July will invariably result in 
brown rot, for with the slowing-down in growth the healing powers of 
the fruit are not sufficient to overcome infections. Furthermore, the 
extent to which the fruit may be injured and still recover depends much 
on the number of apples on the tree, as well as on the rate of growth at 
the time of injury. These factors are dwelt upon more at length else- 
where in this paper. 

The codling moth 

{Carpocapsa pomoncUa Linnaeus) 

The codling moth is the oldest, the most destructive, and probably the 
best-known pest on the fruit of the apple. The moderately large, pink- 
tinted larvae are only too frequently found boring through the flesh of the 
fruit and forcing out the brown frass from the exit of their burrows — a 
sight familiar to all who frequent orchards or eat newly ripened apples. 
I'here are, however, certain phases of codling-moth work which are not 
always recognized by the casual observer, and it is these obscure features 
that the writer has sought to present and illustrate herein. 

As an aid to the understanding of injuries produced by the codling 
moth, a review of the life history for a typical growing season is presented 
as observed in western New York during 191 4. The spring brood of 
moths began emerging on June 3, and came forth in greatest numbers 
between June 8 and June 14, or for a period of a week immediately fol- 
lowing the closing of the calyx on the young apples. The eggs were 
probably laid in greatest numbers between June 10 and June 20, and the 
newly hatched larvae l)egan entering the fruit about June 10 and were 
entering in maximum numbers up to the end of the month. From July 
I on. the larvae entered the fruit in gradually decreasing numbers through 
the period up to July 25. The last moth to emerge in the cages, from the 
larvae kept over winter, came forth on July 15, and in the orchard this 
moth might have been expected to lay eggs as late as July 25. 

The first larva of the spring brood which was observed to have com- 
pleted its growth did so by July 6. and others were found to ho. leaving 
the fruit on July 8 (Plate XII, 38). Several trees in an unsprayed 
orchard were stripped of the rough bark and then kept continuously 
banded with burlap. In this way most of the larvae that completed their 
growth and sought suitable places under the bark for spinning cocoons 
were always found in the burlap. Several such larvae were taken from 
the bands on July 11. These larvae spun cocoons immediately on enter- 



464 Bulletin 410 

ing the burlap bands, pupated within three days, and after a rest period of 
ten days began emerging as moths of the second brood. In the cages the 
first moth of the second brood came forth on July 24, but the majority 
of those that emerged appeared between July 28 and August 10. From 
these data it is apparent that the egg-laying period of the first-brood moths 
extends up to and may slightly overlap the appearance of the second-brood 
moths. I 

Larvae that had been collecting since August 3 were taken from the 
bands on August 8, and from this lot one or more moths emerged each 
day between August 15 and August 27. The larvae that entered the 
bands on the trees after August 8 did not transform, but remained in the 
krval stage until the following spring. The larvae produced by the late- 
emerging second-brood moths were always abundant in the unsprayed 
orchards during September, and a few were to be found attacking the 
fruit practically up to picking time. The line of demarcation between the 
two broods of larvae is not apparent from the work on the trees, since the 
work of the late first-brood larvae is similar to that of the " side-worm " 
injuries produced by the second brood. During the. last ten days of July 
it was always possible to find a few tiny larvae just entering the fruit, and 
these could not be assigned with certainty to either brood. The last larva 
that the writer could assign definitely to the belated first-brood moths was 
found entering an injured Baldwin apple on July 20 (Plate XIV, 
46), working its way in at the bottom of a scar produced by the fruit-tree 
leaf roller. Thus it is seen that the two broods of moths overlap in their 
period of activity and there is a time during which larvae from both broods 
are to be found entering the fruit. 

From these observations and similar ones made during 191 3, 191 5, and 
1916, it may be stated that in western New York the codling moth pro- 
duces one full brood and a partial second brood, the size of the latter 
depending apparently on the character of the season. The method of 
attack by first-brood larvae is fairly well known, in that the majority 
of the young larvae enter the fruit by way of the calyx end. It is the 
habit of the larva to always seek some depression on the surface of the 
fruit; when the apple is small it is usually the calyx cup, but later, when 
the apple is large, the point of entry may be at any break or scar in the 
fruit skin or at a spot where a leaf rests closely against the apple. After 
feeding for a short time in the calyx cavity, which is its usual procedure 
in June, the young larva works its way to the center of the fruit, where it 
devours some of the seeds and the core tissue. After the fruit has 
attained considerable size, the newly hatched larva is as likely to enter on 
the side or the stem end as to find its way to the calyx cup. It rarely 
enters, however, on the smooth exposed surface of the apple, preferring 



Insects Affecting the Fruit of the Apple 465 

to work in at some slight depression, at a contact point between two 
apples, or where a leaf gives some protection from the sun. When nearly- 
grown the larva invariably works its way to the surface of the fruit and 
begins forcing excrement from the burrow (Plate XIV, 43), and this 
frass, taken with the premature ripening of the fruit, is a certain indica- 
tion that the codling-moth larva is at work. The exit hole is kept care- 
fully closed with frass, probably as a protective measure against parasites 
and predacious enemies. But when growth is completed, the larva departs 
from the fruit, forcing out the frass plug. An open burrow is a sure 
indication that the larva has deserted the fruit and gone in search of a 
suitable place in which to spin a cocoon. 

By the end of June and during the first week of July, when the apples 
are about one inch in diameter, the larger and more advanced of the first- 
brood larvae begin forcing out the characteristic brown frass from their 
burrows. The apple shown in section in Plate XII, 38, illustrates this 
very well, the larva being fully grown and practically ready to leave the 
fruit. The exit to the burrow is most frequently in close contact with a 
leaf or at a point where two apples rest in contact (Plate XIII, 40), and 
such a condition probably lends some protection to the larva against its 
parasitic enemies. The extent to which the codling-moth larva may bur- 
row in the small fruits is shown in Plate XII, 38, photographed on July 
8. Such apples invariably drop within a few days, but the larva leaves 
the fruit first unless a storm or an unusual wind intervenes^. During the 
latter part of July, when the apples are much larger, the feeding larva 
gradually works its way to the core of the fruit, where it feeds on the seeds 
and the surrounding pulp. In Plate XII, 39, is illustrated the kind of 
cavity that the larva makes in a large apple. The two apples shown in 
Plate XIII, 40 (photographed on July 28) present the characteristic 
appearance that results when two or more larvae begin work where two 
apples rest in contact. The apples were spread apart for the photograph 
and the work of more than one larva may be detected. Probably three or 
four larvae started work between the two apples, and the two that sur- 
vived until the photograph was taken had been at work perhaps not more 
than ten days. 

The codling-moth larvae that enter the apple during the latter part of 
July and in August and September, most frequently enter at some scar, 
at some abrasion of the skin where two apples touch one against the other, 
or under a leaf that lies in close contact with the fruit. A high propor- 
tion of the larvae evidently do not succeed in entering far into the apple, 
but die from various causes soon after making a small opening through 
the skin of the fruit. The tiny newly hatched larvae probably seek the 
shaded and protected parts of the fruit for definite reasons. In fact, few 



466 Bulletin 410 

if any larvae ever succeed in entering on the side of the apple where the 
hot sunshine beats upon it. It is apparent that the young larvae are not 
able to w^ithstand the excessive amount of sap that issues from a fresh 
wound. This is particularly noticeable if the sun shines hotly upon the 
fruit, for many larvae are found dead apparently from the effects of the 
hot sap that boils out. If the larva is successful in its efforts to enter the 
fruit, a white frothy spot covers the point of injury (Plate XIII, 41). 
This frothy spot gradually dries up and turns to white powder, soon to be 
followed by brown excretions from the larva. The larva remains near the 
surface for five or six days, gaining slightly in size and strength in order 
that it may be able to withstand the sap pressure which it must resist 
while working its way to the core. Having arrived at the core, the larva 
finds air space about the seeds and plenty of food; thereafter its chances 
of attaining maturity are very good. 

On one occasion (September 12) a large apple was cut in section, and 
in the seed cavity was found a small white larva about one-third grown. 
A slender burrow indicated that the larva had worked its way in from 
the stem end of the apple. This particular larva was unusually white, 
with the head and the cervical shield black — effects possibly produced by 
an exclusive diet on seeds. The larva was so unustial in color that it was 
reared, in order to make sure that no other species was involved. 

In Plate XIII, 41, is shown a pippin apple on which eleven young 
codling-moth larvae had tried to enter on the side of the fruit that was 
shaded by leaves. The tree had been sprayed on August 6, and apparently 
some of the larvae had died from the effects of the poison, for only five 
of them were found to be alive. The young larva will usually feed for 
two or three days at the surface, and because of this habit many larvae 
get spray poison but not before the skin of the fruit is punctured and a 
pinhole injury is produced. Large numbers of perfectly shaped apples 
must be discarded in the grading process due to the small pinhole injuries 
that result from the efforts of young larvae to enter the fruit, and, even 
though the larvae die in the attempt, the injury is not prevented (Plates 
XIII, 42, and XIV, 47). Slices with pinhole injuries, taken from apples 
that were sprayed for second-brood larvae, are shown in the latter figure. 
In case the larva was not killed, a white exudation persisted about the 
point of injury (Plate XIV, 47, a) ; while in case the larva died, the spot 
turned brown and dried up. The white deposit probably resulted from 
the evaporation of the excess fruit juice liberated by the young larva, 
rather than from any product of excretion. During August and Septem- 
ber the apples that are exposed to sunshine will invariably develop color 
around the pinhole injuries (Plate XIII, 42). much as they do around 
scale insects. The color serves to enlarge the spot and make it more con- 



Insects Affecting the Fruit of the Apple 467 

spicuous. All such spots, in fact all pinhole injuries, soon become much 
enlarged, due to the development of brown rot. At picking time all but 
the more recent pinhole injuries appear as brown, sunken spots having a 
tiny hole at the center (Plate XIV, 47). When undisturbed by rubbing, 
the smallest and most recent pinholes will show the characteristic white 
powdery substance about the opening (Plates XIII, 42, c, and XIV, 47, a). 

Rarely, if ever, do two codling-moth larvae come to maturity in the 
same apple ; when more than one larva is present in a fruit they fight for 
possession, the conqueror usually devouring the vancjuished. The Rhode 
Island Greening illustrated in Plate XIV, 43 (photographed on Septem- 
ber 26), shows excessive tunneling for one larva. It has four exits to 
the surface, one on each side with the plug removed as if two larvae had 
departed from the fruit. In Plate XIV, 44, the same apple is shown in 
section, with all the tunnels more or less connected at the core but not like 
the common runway of a single larva. Brown rot, which invariably 
develops in the larval tunnels, is clearly shown surrounding the right-hand 
tunnel. 

Various species of flies, particularly PoUcnia rudis and several large 
species of muscids, are frequently found feeding and enlarging holes that 
were started by the young second-brood codling-moth larvae (Plate XIV, 
45). The flies sip up the juices found in the brown-rot spots and thus 
enlarge the primary injury into a deep, rounded hole, in many cases clean- 
ing out the brown rot down to the living tissue. 

The lesser apple -worm 

(Eiianiionia prunivora Walsh) 

The lesser apple worm has frequently been confused with the codling 
moth, and is in fact closely related to that species but is much less 
abundant in New York. The full-grown larva is very similar to that of 
the codling moth, but is smaller and on close examination can be dis- 
tinguished by the comblike structure on the caudal curvature of the anal 
plate. The work of the lesser apple worm during August and September 
can readily be distinguished from that of the codling moth by the nature 
of its burrows. In its early stages, at least, the larva remains near the 
surface of the fruit, eating out a blotched mine consisting of numerous 
tunnels just beneath the skin of the fruit (Plate XIV, 48). When half 
grown it may eat its way to the core, as shown in the section at the left 
of the figure. This section, taken from just beneath the typical surface 
mines, shows that the larva had made at least four tunnels to the core. 
The larvae of this species continue working on the apples until picking 
time, and any undetected larvae that have a start on the fruit may con- 



468 Bulletin 410 

tinue work even after the fruit has been placed in barrels. The work of 
the lesser apple worm is the most likely to be confused with that of the 
red-banded leaf roller {Eiilia velutinana) , described later; but in the case 
of the latter species, the skin of the fruit is eaten as well as the flesh 
underneath. 

The fruit-tree leaf roller 
{Ar chips argyruspila Walker) 

The larvae of the fruit-tree leaf roller, when numerous on apple trees, 
may be very destructive to the fruit. The eggs of this species hatch at 
about the time when the fruit buds are swelling and separating slightly 
at the tips. The tiny larvae immediately bore into the fruit buds and 
begin their destructive work by destroying fruit clusters before the fruit 
is set. By the time the tree is in full bloom, the larvae have begun to 
spin silken threads, drawing together the blossom cluster with the new 
leaves into a loosely woven nest within which they feed. By the time the 
petals are falling, one larva will have destroyed a single fruit cluster ; and 
as soon as the young apples begin to form, it will move to a new cluster, 
there to begin devouring the newly formed fruit (Plate XV, 49). As 
the apples grow larger, cavities are eaten into them by the larva, which 
remains close at hand in a rolled and webbed leaf that serves as a retreat 
(Plate XV, 50). One may frequently see a larva reaching out from its 
retreat and feeding at the base of an apple. This is a characteristic habit 
of the larvae after the apples have attained one-half inch or more in 
diameter. Usually the open end of the retreat is in close contact with the 
fruit, and so the feeding operations cannot be easily observed. 

During the last ten days of June, after the apples have attained from 
one-half to three-fourths inch in diameter, the majority of the fruit-tree 
leaf -roller larvae complete their growth and change to pupae. Nearly all 
of the fruits injured by the larvae prior to June 20 drop as a result of the 
injury. Many of the apples fed upon after that date also drop, but the 
number of these is largely dependent on the abundance of fruit on the 
tree. As in the case of injuries by the apple redbugs, it is the weakest 
or the injured fruits that drop first ; when there is a heavy set of fruit, the 
larvae may actually help thin the fruit, but when the set is light, many of 
the injured fruits will recover and grow to maturity, showing an ugly 
scar. The growing season of 1914 was normal and the set of fruit was 
heavy, and as a result the majority of injured fruits did not survive the 
June drop. An estimate for 1914, determined by counting the fruits 
tagged and by constant observation of the fruit injured after the apples 
had set, would place 95 per cent of the injured apples as dropping, and 
5 per cent as recovering and growing to maturity showing a scar. In 



Insects Affecting the Fruit of the Apple 469 

orchards that were badly infested by the fruit-tree leaf roller, at least 10 
per cent of all the apples that remained on the trees showed scars caused 
by this insect. Apples that grew to maturity showing a scar were those 
injured by late feeding of the larvae, for the most part after June 20. 
The tag experiments showed that all fruits injured prior to June 18 
dropped, and only a few of those injured on June 18 and 19, which had 
the advantage of having all near-by fruits pruned away, were able to sur- 
vive. The typical deep injuries made by the larvae after June 20 are shown 
in Plate XV, 51 and 52. These apples were picked and photographed on 
June 24. They would have recovered and grown to maturity showing 
typical scars, as did others similarly injured. 

During early July, the apples that remain after being injured by the 
feeding larvae rapidly form a new surface over the wound ; at first a 
brown, corky layer of dead cells covers the wound, but this soon cracks 
and falls away following the formation of new skin beneath. The mature 
scar has a bronze color and a slightly roughened surface. The character 
of the scar, as well as the ability to recover from the wound, varies accord- 
ing to the variety of apple afifected. The power of recovery from wounds 
is particularly noticeable in the pippin and Twenty Ounce apples. Those 
apples that gain in size very rapidly may recover and grow to maturity 
even though the seeds have been eaten out. In Plate XV, 53, are shown 
three pippin apples, at picking time, which had been fed upon and had 
part of the core removed and yet grew to maturity. This may happen 
occasionally with a Rhode Island Greening or a Baldwin apple, but is 
rather unusual with these varieties. Typical leaf-roller work on Baldwin 
apples may be seen in Plate XVI, 57. In Plate XV, 54, is shown injury 
to Twenty Ounce apples (photographed on July 8) in which the feeding 
larvae reached the core on June 20 ; the smallest apple was ready to drop, 
but the others were recovering and would have attained maturity. On 
pippin and Twenty Ounce apples one may find unusually large scars made 
by the leaf-roller larva. Since these varieties grow very rapidly, the small 
feeding cavities made by the leaf roller will be expanded with the growth 
of the fruit until the scars are comparable in size to the work of green 
fruit worms on Baldwin and Northern Spy apples. 

Very few leaf-roller larvae are to be found at work later than July i, 
Init the few that do work late produce some unusual scars which may 
prove difficult to identify. The scars that result from the work of larvae 
feeding as late as June 30 are unusually small and shallow. Such scars 
may sometimes be very similar to the shallow wounds produced by green 
fruit worms (Xylina spp.). However, the work of the fruit-tree leaf- 
roller larva can usually be recognized by the fact that some part of the 
scar will show a deep or a narrow excavation. Comparison between the 



470 Bulletin 410 

work of leaf-roller larvae and the work of fruit worms is shown in Plate 
XVI, 55 and 56, photographed nearly two weeks after the injury occurred. 
The broad, shallow work of the fruit worms is readily distinguished from 
the deeply excavated or narrow channels produced by the leaf-roller larvae. 
The work of the leaf roller shown in Plate XVI, 55, was selected as a 
sample of some shallow excavations, which is not the usual or typical 
work of the species and yet can be recognized as different from the broad, 
shallow work of fruit worms. Unvisual types of scars caused by the leaf 
roller are shown in Plate XVI, 58 and 59. In rare cases the larva may 
move to a new apple only two or three days before it is ready to pupate, 
or it may be forced to abandon an apple prematurely, and in such cases 
typical scars would not result (Plate XVI, 59). The deep excavation in 
the Twenty Ounce apple shown in Plate XVI, 58, has been filled out by 
growth and to some extent produced a warted surface. Scars of all types 
may show accelerated growth if the conditions are right to force growth 
late in the summer, after the skin of the fruit has hardened. 

The work of aphids on the fruit always has a tendency to stunt growth 
and harden the stems in such a way that injured or weak fruits are made 
to cling for a much longer time than they otherwise would. In one case 
observed, two apples were severely injured by a leaf -roller larva about 
June 15, but the apples were made to cling until July 8 (when they were 
picked), due to an infestation by the rosy aphid, which developed on the 
fruit cluster about the time when the injury was produced. 

The problem of determining scars may frequently be made difficult by 
the work of two or more species occurring on one fruit. But after suffi- 
cient experience in observing typical scars for each species concerned, 
one may hope to determine accurately 98 per cent of all the scars found. 

The ohliquc-handcd leaf roller 

(Archips rosacea iia Harris) 

The oblique-banded leaf roller occurs along with .irchips argyrospila 
in the orchards of western New York, but is not nearly so abundant. In 
certain orchards one-tenth of all the leaf-roller larvae examined were 
found to be this species. The work of Archips rosaccana on the fruit 
does not appear to differ from that of A. argyrospila. In the field, while 
the larvae are actively at work, one may distinguish A. rosaccana by its 
yellowish brown to pale apple-green color and its brownish black head and 
thoracic shield, as contrasted with the invariably black thoracic shield and 
apple-green color of A. argyrospila. When determining the mature scars 
on apples as the work of leaf-roller larvae {Archips spp.), one is bound 
to include some work produced by A. rosaccana but the percentage will 



Insects Affecting the Fruit of the Apple 471 

be small. A second brood of the A. rosaccaua larvae appears on the 
tender foliage of the trees in July and August, but were not found by the 
writer to infest the fruit. 

The green fruit zvorm 
(Xylina antcnnata Walker) 

In western New York the commonest species of green fruit worm 
attacking the apple is Xylina antcnnata. The over-wintering moths come 
forth to lay eggs on the apple twigs before the buds have turned green. 
The eggs hatch during the first warm days, and the tiny larvae begin 
feeding on the tender leaves as soon as the buds begin unfolding. By 
the time the fruit is formed, the larvae are half grown, and, having a 
voracious appetite, are capable of devouring the young apples rapidly. 
The larva of this species is usually distinguished by the green color, the 
broad white lateral line, and the numerous small pale spots on the latero- 
dorsal surface. In 1914, which may be considered as a normal season, 
some of the larvae had completed their growth by June 15, or before the 
apples were one-half inch in diameter ; others were more retarded in their 
development and did not finish feeding before June 20, and a few even 
later. The larvae that fed on the fruit on June '18 and later, were the 
ones producing the scars that showed on the apples at picking time. 

The fruit worm is large when the apples set, and consequently the 
effect of its feeding is to cause the fruit to drop. When the apples are 
small, many of them are completely eaten. Only after they are one-half 
inch in diameter, and when growth is rapid, are they able to recover. A 
comparison is shown in Plate XVII, 60, between a fresh half -eaten apple 
injured by the green fruit worm, and an apple showing the deeply exca- 
vated and smaller scar produced by the larva of the fruit-tree leaf roller. 
This difference in scars is nearly always apparent, particularly in freshly 
injured apples, in which the broad, coarse, mandible marks of the fruit 
worm may be distinguished. A nearly full-grown larva of Xylina 
antcnnata is shown in Plate XVII, 61, excavating a deep, narrow wound 
to the core of an apple, but this manner of feeding is unusual. In a few 
cases a fruit-worm larva was found entirely inside an apple, having eaten 
out the core and enough of the pulp to form a retreat within. As a rule 
the larvae are intermittent and restless in their habits, feeding on one 
apple for a short time and then moving to another. This habit makes 
the fruit worm much more destructive than it would be otherwise, for the 
apples that are only slightly injured are likely to recover and grow to 
maturity showing a scar. The small scars made by a larva about June 10, 
when it was only about one-third grown, are shown in Plate XVII, 64. The 



472 Bulletin 410 

injury was so slight that the apples were recovering and the scars had 
healed over by June 24, when the photograph was made. One larva often' 
feeds on a dozen or more fruits, or on all the apples on one small limb. 
The way in which one larva may feed on several fruits is well illustrated 
in Plate XVII, 65, showing how several pears on one limb were fed upon 
by a single larva but all recovered and bore ugly scars. 

The broad scars produced by fruit worms on or before June 18 are 
usually so severe that the apples rarely recover, and yet in a few cases, 
where the set of fruit is light and growth is forced by warm rains, the 
fruits may grow to maturity. Scars made on June 20 are shown in Plate 

XVII, 62, as they appeared on June 24; the scars have turned brown, 
which is the first stage in the healing process. In Plate XVII, 63, are 
shown two apples that were injured on June 18; on June 24, when the 
photograph was made, the scars were rapidly healing, as is indicated by 
a few cracks in the brown corky layer composed of cells that died from 
the injury. A Rhode Island Greening apple which was injured on June 
18 by the intermittent feeding of a green fruit worm is shown in Plate 

XVIII, 66, as it appeared on August 14. The broad, shallow scars are 
characteristic of fruit-worm injury but may sometimes be confused with 
the work of the white-marked tussock moth, discussed later. In one 
experiment a green fruit-worm larva was observed to feed on six apples 
from June 18 to June 20 inclusive, and during this time each apple 
received one or more feeding scars. This experiment was typical of the 
intermittent feeding in which several apples are only slightly injured, the 
scars being shallow and not very broad. 

A comparative study of the scars made by green fruit worms on differ- 
ent varieties of apples shows some of the same differences developing 
that were noted in studies of the fruit-tree leaf roller and the apple red- 
bugs. Twenty Ounce apples and pippin varieties were found to recover 
when severely injured, in many cases even after the core had been partly 
eaten. A most unusual recovery after injury by a green fruit worm was 
shown by a pipi^in apple (Plate XVIII, 67) in which the core and half 
of one side were eaten away, and in addition the larva devoured a part 
of the opposite side. The same apple if turned slightly would show how 
the scar extends to the center of the core, the new tissue folding inward 
over the cavity during subsequent growth. An unusual recovery for a 
Baldwin apple is shown in Plate XVIII, 68 ; a fruit worm ate part of the 
core on June 25, but the apple recovered and grew to maturity. For fruit- 
worm work this scar is rather small and deep, and might be confused with 
certain scars produced by the fruit-tree leaf roller. 

The usual kind of scars produced by the green fruit worm and found 
on the fruit at picking time, is shown in Plate XVIII, 69 and 70; scars 



Insects Affecting the Fruit of the Apple 473 

appearing in the forim of large wounds, more or less shallow, perfectly 
healed, bronze in color, and usually with bits of dried corklike tissue still 
clinging in places. Apples so injured keep perfectly in storage, but the 
disfiguration is taken as sufificient reason for discarding them in the grad- 
ing process. Baldwin apples with typical scars are shown in Plate XVIII, 
70. A scar on a Tompkins King apple which in outline is somewhat sug- 
gestive of the injury produced by the white-marked tussock moth, is 
shown in Plate XVIII, 69; but the old and dried-out corky tissue clinging 
to the scar indicates a period of healing prior to the time when the 
tussock-moth larvae begin their work. 

The green fruit worm 

{Xylina laticincrca Grote) 

Another green fruit worm, which is second in abundance in western 
New York, is Xylina laticinerea. The larva of this species is distin- 
guished from X. antcnnafa by having a more slender white lateral line, 
and a median dorsal line equally distinct. The habits of both species are 
very similar and no distinction can be drawn between the injuries they 
produce. A larva of X. laticinerea, nearly full-grown, is shown in Plate 
XIX, 71, with four young apples on which it was feeding on June 18. 
The broad, rough scars produced by fruit worms are well shown in this 
photograph. 

The red fruit worm 

(Rhynchagrotis placid a Grote) 

A species conspicuous because of the red color of the larva, and occa- 
sionally found feeding on the apple in western JSIew York, is Rhyiicha- 
c/rotis placida Grote. The larval habits of this species are slightly dififer- 
ent from those of Xylina spp. Rhynchagrotis placida has been classed as a 
climbing cutworm, and such larvae are supposed to climb up the trees only 
at night for feeding. The writer occasionally found larvae of this species 
resting during the day, if not feeding, within the cavities they had eaten 
into the apple. When disturbed they curl up, as is the habit of certain cut- 
worms, and in this respect they differ from species of Xylina. The larvae of 
R. placida are rather sluggish and do not move from one apple to another 
as freely as do the green fruit worms. Because of this habit, the apple 
fed upon usually shows two or three irregular scars. A Rhode Island 
Greening apple which was fed upon by one larva from June 16 to June 
19 is shown in Plate XIX, 72 ; the photograph was made on August 16, 
and shows several irregular scars that resulted from the work of the larva. 
A Baldwin apple with a large, irregular scar is shown at maturity in Plate 



474 Bulletin 410 

XIX, 73. In each case the scars are large and very irregular, deep in 
some places and shallow in other parts — characters that may often enable 
one to recognize the work of this s^jecies. The age of the healed surface, 
being similar to that in the case of injuries produced by green fruit 
worms, will serve to distinguish the scars from those made by the tussock 
moth at a later date. 

The white -marked tussock iiiotJi 
{Hemerocampa leucostigma Smith and Abbot) 

The white-marked tussock moth was found very abundant in a few 
apple orchards in Genesee County, Niew York, and became very destruc- 
tive to the fruit. The Qgg masses, which remain on the trunk or the large 
limbs of the trees all winter, do not hatch until after the trees bloom and 
the fruit has set. The young larvae are not large enough to attract atten- 
tion or feed on the fruit until about June 20, but, having started, they 
keep up their destructive feeding until after the June drop occurs, some 
larvae feeding as late as July 12. Consequently the injuries they produce 
are more likely to be in evidence as scars on the mature apples, since the 
fruits in most cases are large and are able to withstand the shallow feed- 
ing which occurs after June 25. 

The larvae of the tussock moth normally feed on the tender foliage of 
several varieties of trees, but when they occur on apple trees they show 
a decided preference for the young, green apples. In observations on 
the feeding habits of the larvae it was noted that the early feeding (June 
22) had a fatal effect on certain of the injured apples. The injured 
fruits were given such a setback in the struggle for sap and existence 
that the uninjured members of the fruit cluster outstripped the injured, 
with the result that many succumbed in the June drop which followed. 
Two larvae scarcely half-grown, feeding on the fruit on June 24, are 
shown in Plate XIX, 74. The larvae are restless in their habits, feeding 
for a short time in one spot and then moving to a new place. This habit, 
combined with shallow feeding, produces several scars on the same apple 
— a condition that enables one to recognize a high proportion of the scars 
produced by this pest. Two young Baldwin apples, photographed on 
July 4 (Plate XX, 76), show characteristic scars produced by the inter- 
mittent feeding of the half-grown larvae. As the apples get larger, one 
larva often remains feeding on the same fruit for five or six days (Plate 

XX, 75). The first scars produced begin healing while the larva still 
feeds on other parts of the same fruit. Some larvae may continue feeding 
on the fruit as late as the middle of July, but after the apples have grown 
larger and the skin has become tough the larvae are more likely to move to 
the tender new leaves to complete their growth. 



Insects Affecting the Fruit of the Apple 475 

After the middle of July the apples grow more slowly, and, as a result, 
injuries produced later than July 12 heal but very slowly and imperfectly. 
In fact, some of the tussock-moth larvae feed on the fruit until it is 
unable to replace the injury with new skin. Two Northern Spy apples 
photographed on July 20 (Plate XX, 79) show the long, shallow channels 
which the larvae make after the skin has hardened and is no longer tender 
to their liking. These fruits were injured between July 12 and July 15, the 
injured part drying out and shriveling slightly — the first indication of 
improper healing. A Rhode Island Greening apple photographed at pick- 
ing time is shown in Plate XXI, 81 ; the scar is rough and hard, not hav- 
ing the smooth skin beneath as is found on scars that heal while the fruit 
is growing rapidly. Excessive late feeding by the tussock moth on a 
Rhode Island Greening, is shown in Plate XXI, 82, the injuries having 
been made so late that brown rot would have developed had the apple 
been an early-maturing variety. A Twenty Ounce apple which was fed 
upon by a tussock-moth larva after the middle of July (Plate XX, 80) 
shows how brown rot may start in any wound that occurs after the fruit 
has stopped active growth. 

The mature scars produced on apples by the tussock moth may present 
curious shapes and forms. The scars may be recognized, however, by the 
following combination of characters : ( i ) scars always shallow, fre- 
quently imperfectly healed; (2) scars irregular in outline, exhibiting 
slender feeding tracts; (3) several small, perfectly healed, irregular scars 
on one apple, or one or more large, rough scars having narrow, irregular 
tracts at some points on the margin. The work of the larva during the 
last week in June is characterized by intermittent feeding, the larva start- 
ing a new feeding place at any point where it may happen to be when 
hungry. Such scars heal with a smooth surface, since the apple is grow- 
ing rapidly. Later, when the skin of the apple has begun to get tough, 
the larva does not like to make a new puncture, but wanders around until 
it finds the previous point of feeding, there to enlarge the wound or to 
extend it in narrow channels as it feeds. On one Rhode Island Greening 
apple observed, ten small surface scars were counted, all made by one 
tussock-moth larva ; some of the scars were so small that they strongly 
suggested the work of the pistol case-bearer. Three larger and more 
irregular scars are shown in Plate XX, yy. A large, sinuate scar, typical 
of the tussock-moth work, is shown on a Rhode Island Greening apple in 
Plate XX, 78. This injury was produced near the end of the period 
when perfect healing would take place, and consecjuently the skin of the 
apple was then becoming so tough that the larva preferred to feed by 
enlarging one spot rather than making new ones. 



476 Bulletin 410 

Warting of scars was found to take place on tussock-moth injuries, 
as noted in the case of other scars, whenever the conditions were right to 
produce such effects. A large mature scar on a Jonathan apple is shown 
in Plate XXI, 83, in which the scar tissue has bulged out above the general 
surface due to new and unusual growth just beneath the scar. Such 
warting is caused by accelerated growth after the skin of the apple has 
become hardened ; the scar tissue, being formed later than the skin on 
the other part of the apple, gives way at the point of least resistance under 
the pressure caused by new growth. In Plate XXI, 84, a small scar 
caused by the tussock moth is shown in comparison with an old scab 
spot, which also shows the effect of warting under pressure by growth 
late in the season. 

The palmer ivorm 
{Ypsolophus ligtdellus Hiibner) 

In some years the palmer worm is very destructive to apples, but thus 
far such years have been few and far between. The species is known to 
have been very destructive in New York in 1853, and not again until 1900. 
It is evidently always present in apple orchards but in very limited num- 
bers. During the years from 191 3 to 19 16, inclusive, while the writer 
was constantly inspecting orchards in western New York, he found 
palmer worms in only a few orchards and usually as isolated specimens. 
The larvae were found in greatest numbers in two orchards which had 
suffered from neglect. 

Although material lor study was scarce, observations ^ere made and 
photographs were obtciined showing the character of the wounds pro- 
duced by the palmer worm. No larvae were observed feeding on the fruit 
I)efore the middle of June, but larvae found after that date were always 
working on the fruit. A typical example of the injuries produced during 
the latter part of June is shown in Plate XXI, 85, taken on June 25. The 
small, slender larvae, marked with pale longitudinal lines and with two 
broad dark stripes, move with a wriggling motion when disturbed, fre- 
quently abandoning the web-covered retreat on the fruit and dropping 
below on a silken thread. After feeding for three or four days on' one 
apple, the larva invariably secretes itself under a web spun over the cavity 
which it has eaten into the fruit. Bits of web remain in the wound long 
after the injury is made (Plate XXII, 86), serving to identify the pest 
that did the damage. In Plate XXII, 88, is shown an apple, photographed 
on August 12, in which the larval web may still be seen in the scar. 

All fruits injured before June 20 were found to drop, and only the late- 
scarred fruit, injured after that date, remained on the tree to develop 



Insects Affecting the Fruit of the Apple 477 

mature scars. The late work is characterized by deep and narrow scars 
(Plate XXII, 87). In certain cases in which the web spun by the larva 
is not visible, the work of this species might be confused with the late 
work produced by the fruit-tree leaf roller. In the case of a Roxbury 
apple photographed on July 21 (Plate XXI I, Sy), there are to be seen five 
small holes grouped closely together, the work of a larva during the last 
three days of June ; but the bits of web found still clinging to the wound 
would serve to identify it as the work of a palmer worm. 

The bud moth 
{Tmcfoccra ocellana Schiffermiiller) 

The bud moth is well known as a pest chiefly because of the damage 
which the larvae may do by eating into the young fruit buds during May, 
thus destroying the crop before the fruit is formed. When abundant, 
this insect may also do considerable damage to the maturing fruit, and, 
for the present study, observations are recorded on this phase of the 
insect's activity. 

The larvae that destroy the buds in spring, change to pupae during 
June. After ten days in the pupal stage, or during the last few days in 
June and the first two weeks of July, the moths come forth to lay their 
eggs on the leaves. In the latter part of July, the tiny, black-headed 
caterpillars hatch from the eggs and begin to feed on the under side of 
the apple leaves. All during September the small, reddish brown larvae 
may be found feeding on the under side of the leaves, usually hiding 
beneath a protective layer of web. this being constantly rebuilt to cover 
new feeding areas, ^^'hen a leaf bearing a larva comes in contact with 
an apple, the leaf is frequently drawn against the fruit and firmly attached 
to it with web. Within this safe retreat the larva continues to devour 
parts of the leaf, and in addition it may eat several small round holes 
through the skin of the apple. The first work of this kind on fruit was 
found on August 8 (Plate XXII, 90), the larva having fed extensively 
on the leaf but having made only four or five holes through the skin of 
the fruit when disturbed. The same type of work is better shown on a 
Pound Sweet from which the leaf was turned back and photographed on 
September 15 (Plate XXII, 89). Even in well-sprayed orchards, many 
apples will be found that appear to be perfect and yet when they are 
picked a leaf is found sticking to one side, beneath which the work of the 
bud moth is revealed. 

The work of bud-moth larvae on the maturing fruit may invariably 
be distinguished by a group of small holes eaten through the skin, while 



478 Bulletin 410 

the light area about the injury indicates that a leaf has been held in con- 
tact with the spot sufficiently long to make an appreciable difference in 
color. In case the injury has not been rubbed, bits of web and a white 
powder may be found about the scars. Although the wounds made in the 
fruit by the bud moth during September are small, when careful grading 
of the fruit is done or apples are selected for show purposes many per- 
fectly shaped apples will need to be cast aside or relegated to the inferior 
classes due to these small feeding punctures. 

Tlic rcd-haudcd leaf roller 
(Eulia vclntinana Walker) 

An insect that was doing a slight amount of damage to the fruit dur- 
ing August and September proved to be Eulia %'clutinaua Wal!:er, a 
species not ordinarily recognized as a pest- on the apple. On July 28 the 
writer first noticed a larva of this species which was feeding in an unusual 
manner between two Genesee Flower apples (Plate XXIII. yi). This 
larva, with the apples, was placed in a breeding jar. where it pupated 
within a curled leaf on August 2. When full-grown the larva is very 
suggestive of Archips argyrosplla, but is slightly smaller than that species. 
From the pupa developed on August 2, a moth emerged on August 11. 
The moth of this species has a tuft of hairlike scales on to]) of the thorax, 
is slightly smaller than that of Archips argyrospila, and has much less 
of the dark brown color. The spread moth is shown, somewhat enlarged, 
in Plate XXIII. 92. 

The work of llidia vclutinana was frequently found on the fruit dur- 
ing August and September, and a few larvae were still at work when the 
truit was picked. The larva is a surface feeder, evidently never eating 
deeply into the fruit as is done by the fruit-tree leaf roller. A tvpical 
example of the work found during x^ugust may be see'i in Plate XXIII, 
93. The larva prefers to live and feed on the fruit while secretin r itself 
beneath a leaf or by working between two apples that rest in contact. 
Sometimes a detached leaf is fastened to the fruit with web, and this 
serves as a retreat or protection from which the larva can feed. Late in 
the season a decided preference is shown by the larvae for eating only 
the skin of the fruit (Plate XXIII, 94). A Baldwin apple which had 
been kept in a barrel for two months was found to have on .November 29 
fresh shallcw scars, such as the late-feeding lar\ a will produce, and 
attached to the fruit was some wel) in which the larva had secreted itself. 

The work of Eulia icluiinaua during August and September may be 
dist'nguished by the broad and shallow feeding scars, which never heal 



Insects Affecting the Fruit of the Apple 479 

due to the lateness of the season. No other species was found to be doing 
a type of work that could be confused with the scars here illustrated. The 
damage to fruit caused by this species is doubtless done by larvae of a 
second brood, though the complete life cycle is not known. 

The pistol casc-bcarcr 
{Colcophora inalvvorclia Riley) 

Case-bearers are interesting little insects, for the larvae of each species 
live within and carry about with them a case of a particular pattern com- 
posed of leaf fragments. The pistol case-bearer always constructs a case 
which in form resembles a pistol case. In western New York the pistol 
case-bearer was frequently found infesting apple trees, and particularly, 
those orchards that had not received a thorough spraying just before the 
flower Inids opened. The young larvae hil)ernate in tiny cases attached 
to the twigs of the tree, and as soon as the buds show green they move 
from winter quarters and cluster on the unfolding tender leaves. 

As soon as the fruit sets, many of the larvae find their way to the 
young apples and begin feeding. The case-bearer larva feeds by making 
a round, deep hole through the skin of the fruit, and then mining out the 
parenchyma in all directions a^ far as it can reach without entirely desert- 
ing its case. Having obtained all the food possible at one point, the larva 
creeps along with its case to a new location, settles down, eats through the 
skin, and begins feeding as before. Pistol case-bearers, nearly mature, 
are shown in Plate XXIV, 95, at work on young apples on June 9 ; the 
small, round, black holes show points of previous feeding. One case- 
bearer may make several such feeding punctures on one or more apples. 

The larval activity of a single case-bearer is well shown in Plate XXIV, 
97. This larva began feeding on a Twenty Ounce apple, a variety that 
grows so rapidly and attains such size that the case-bearer is unable to kill 
the fruit. The regular progression in size of scars is due entirely to the 
effect of growth, the largest scars being those first produced while the 
smallest scars are those made by the larva's feeding after the apple had 
attained considerable size and when little expansion w.as possible by further 
growth. The clear spots in the leaf show the effect of larval feeding on the 
foliage. On completing its growth the case-bearer moved from the fruit to 
the adjoining leaf, and then to the twig, w'here a firm attachment was made 
preparatory to pupation. The moth emerged toward the end of June, but 
the case remained in position for a long time after. The photograph was 
made on August 30, after the apple had attained more than half its growth 
and was apparently stunted somewhat by the injuries received. 



480 Bulletin 410 

The mature scars frequently show a funnel-shaped depression at the 
center, indicating that the cavity produced by the larva is not always 
entirely filled out by growth (Plate XXIV, 96). This feature, combined 
with the numerous small, rounded scars on a single fruit, is characteristic 
of case-bearer work. The large scars that sometimes result from the 
very early feeding of the case-bearer larva might be mistaken for the 
rounded scars made by the tussock moth, were there not a gradation in 
size of the scars. 

In a few instances the scars made by this ca.se-bearer were found to 
produce a splitting of the skin about the wound, very similar to the way 
in which splitting and enlargement of the scar occur with redbug injuries. 
A good example of this is shown on a Detroit Red (Plate XXV, 98), in 
which the contrast between the bronze scar tissue and the red skin of the 
apple is conspicuous. 

Several types of mature scars from Baldwin and Twenty Ounce apples 
are shown in Plate XXV, 100, slices from different apples being arranged 
in a group for purposes of comparison. The work of the case-bearer on 
a crab apple as illustrated in Plate XXV, 99, shows all types of scars and 
particularly the effect of warting. The skin of the crab apple hardens 
early in the summer while growth pressure is still being exerted ; hence 
the more recent and tender scar tissue gives way to the new cell formation 
underneath. 

The cigar case-hearer 
(Coleophora flctchcrella Fernald) 

The second species of case-bearer frequently found in abundance in 
apple orchards is easily distinguished from the preceding species by the 
shape of the larval case. This insect has received the name cigar case- 
hearer. The life history of the species is very similar to that of the pistol 
case-bearer, and the injuries it produces cannot with any degree of cer- 
tainty be distinguished from those of that species. 

The cigar case-bearer, and its work on young apples just formed, are 
seen in Plate XXV, loi, an enlarged photograph showfng well the char- 
acter of the feeding punctures and likewise the shape of the larval cases. 

In this study of the identification of mature scars it was found that the 
work of Coleophora fletcherella could not be distinguished at picking time 
from that of C. malivorella, and for economic purposes the injuries by 
both species may well be classed simply as case-bearer work. 

The work of case-bearers on apples may usually be distinguished as 
follows: (i) by several small, rounded scars of different sizes appearing 
on one apple; (2) by some of the scars showing a funnel-shaped depres- 



Insects Affecting the Fruit of the Apple 481 

sion at the center; (3) in rare instances, when the wound has spHt and 
caused an irregular margin, by the distinctiveness of the funnel-shaped 
depression. 

The fall wehworm 

(Hyphantric textor Harris) 

The fall webworm is a well-known pest on forest and shade trees and 
at times may become abundant in apple orchards. The larvae begin mak- 
ing their unsightly webs on the branches of the trees during July, but 
these are more noticeable during August. The larvae of the fall web- 
worm are essentially leaf feeders, but when they occur on apple trees 
their web nests frequently inclose a few apples. The larvae do not appear 
to prefer the fruit, but when apples come within their range they feed 
upon them. When abundant in an apple orchard the webworms may 
cause more or less damage to the fruit, not only by direct feeding on the 
apples but also by defoliation of the limbs, thus causing a stunting and 
shriveling of the fruit. 

The work of fall webworms on two Alexander apples is shown in Plate 
XXVI, 104. All the leaves on the limb are brown and the fruits are 
covered with web and excrement. The larvae make broad, shallow feed- 
ing tracts over the surface of the fruit, but in places they feed more 
deeply. Two larvae may be seen in Plate XXVI, 102, feeding in cavities 
formed on an Alexander apple. The feeding always occurs so late in 
the season that healing of the wound never takes' place. The scar surface 
usually shrivels and dries out considerably (Plate XXVI, 103). Unless 
the injured fruits have been purposely cleaned, the work of the webworm 
can always be recognized by the presence of web and excrement on broad, 
irregular, shallow scars which never heal. 

The apple serpentine miner 

{Marmara pomonella Busck) 

An insect very interesting because of the peculiar habit of the larvae m 
making serpentine mines in the skin of the fruit, proved on determination 
to be Marmara pomonella Busck. This species was found working on the 
fruit from two localities in New York, but as yet it cannot be reckoned 
as a pest of economic importance. Two types of the serpentine mine made 
by the larva on Baldwin apples are well shown in Plate XXVII, 105 and 
106. In one of these (106) the larva projected its mine in a circular 
course, causing a large blotch on one side of the apple ; in the other, the 
larval mine proceeds in sinuous fashion all the way around the fruit. The 
larva works only between the epidermal and cuticular layers of the apple 



482 Bulletin 410 

skin, thus never causing injury to the flesh of the fruit. The damage, ;f 
such it can he called, is merely a matter of disfigurement of the apple. 
The serpentine mines are made during the latter part of the summer, after 
the apple has attained considerahle size, and thus there is little opportunity 
for the insect to deform the fruit. 

COLEOPTERA 

The coleopterous pests on the fruit of the apple are few in number, and, 
excluding the work of a few occasional infestations by species that are 
general feeders, it may be said that only two species, both belonging to 
the Rhynchophora, are found to feed and develop larval stages in the 
fruit. 

The plum curcul'w 

(Coiiotrachclus ncnupJiar Herbst) 

The plum curculio is known chiefly as a pest on plums and other stone 
fruits, but when these fruits are not availa])le it may cause serious damage 
to apples. In one season the species may breed in large numbers on stone 
fruits, and in the following year, if there is shortage of plums and 
cherries, the beetles will migrate to the nearest apple orchard, there to 
begin their work on apples. 

The plum curculio hibernates as an adult and comes forth in spring to 
the fruit trees, where it takes its first meal, and feeds until such time as 
young fruits are available on the tender, succulent growth. As soon as 
the apples set, the curculios begin feeding on them with ravenous appe- 
tite, and particularly is this true of the females, which are preparing to 
lay eggs. The early feeding punctures are in the shape of round holes 
in the skin of the fruit, through which the curculio excavates all the tender 
pulp that it can reach by inserting its long rostrum. In Plate XXVII, 
107, is shown, slightly enlarged, a curculio resting on a young apple beside 
a typical feeding pyncture that it has just completed. All the fruits 
injured in this manner were found to drop ; since the fruit is so small and 
competition is great, few apples ever survive when injured at such a 
tender age. 

After feeding for a few days, the female curculio is ready to begin 
laying eggs, and this is about the time when the apples are one-fourth of 
an inch or more in diameter (Plate XXVII, 108). The ovipositing 
female makes a small hole in the fruit just large enough to receive the 
egg, then deposits it and cuts a crescent-shaped slit extending in a semi- 
circle around and obliquely beneath it. Such an arrangement doubtless 
prevents the e^gg from being crushed by growth pressure, and especially 



Insects Affecting the Fruit of the xA.pple 483 

protects the young larva at the time of hatching. Young fruits having 
ftg^, crescents, and one with a feeding puncture, are shown for comparison 
in Plate XXVII, 109. Young apples in which curculio eggs have l)een 
deposited will fall to the ground, and if undisturbed the larva will develop 
to maturity. In fact, it seems to be necessary for the apple containing 
the eggs to fall to the ground if the curculio grub is to develop. Rarely 
are apples containing living larvae found on the tree, except late in summer 
when active growth has stopped, and such fruits would fall in any case 
before the larva had worked very far. It is apparent that a softening or 
shriveling of the fruit must occur before the grub is able to make much 
progress. Evidently vigorous growth and strong sap pressure in the fruit 
are more of a barrier to the curculio grul) than to codling-moth larvae. The 
only apple containing an active burrowing grub that the writer has found 
on a tree, was found on July 13 on an unnamed variety (Plate XXVIII. 
112). This fruit was not in an active state of growth, and probably would 
have dropped to the ground before the grub reached maturity. Perhaps 
the lack of sap pressure in the fruit, which permitted the curculio grub 
to start its burrow, was due to causes other than larval activity of the 
curculio. Certain it is that, in the majority of cases, the apple must be 
one that will drop to the ground from causes other than the presence of 
the curculio grub, or else the grub will never have an opportunity to 
develop. 

The injuries caused by the curculio early in the season serve to thin out 
the fruit, but after the young apples have attained one-half inch or more 
in diameter many of them do not succumb to the influence of one or more 
^Z% punctures. Such fruits grow to maturity exhibiting scars, frequently 
being more or less deformed. Three young Baldwin apples with curculio 
scars which may or may not prove fatal to the development of the fruit, 
are shown in Plate XXVIII, 11 1. After June 20 a majority of the 
apples having ^gg punctures do not fall to the ground because of curculio 
injury, but recover and develop scars. On two of the fruits shown in 
Plate XXVIII, III, a white exudation may be seen on the crescent flap, 
indicating that the larva has hatched and is making some effort to feed. 
Rarely does one find curculios that have come out of hibernation making 
simple feeding punctures after the middle of June, since in excavating 
each &gg crescent a certain amount of pulp is eaten. In Plate XXVII, 
no, a beetle is seen excavating a typical round feeding cavity, a result 
obtained by keeping the curculio in a jar where it could not feed for three 
or four days. The male curculio might be expected to make feeding 
punctures which would result in a scar slightly different from the well- 
known crescent of the egg-laying female. The males, however, apparently 



484 Bulletin 410 

feed so seldom following the first great feast, when the young fruits set, 
that rarely, if ever, can scars be found that would appear to have developed 
from plain feeding punctures. 

In an experiment to get data on the feeding habits of the adults, a 
curculio was caged with a single apple from June 29 to July 6. The apple 
succumbed to the injuries and fell on July 20, with the result shown in 
Plate XXVIII, 113, photographed on July 21. Normally the apples that 
have received only a few egg punctures by the end of June or early July 
will recover and grow to maturity. 

Many of the wounds made by the curculio on Roxbury apples during 
July were found to develop brown rot, as is shown in Plate XXIX, 116. 
Several of the punctures appear as rounded cavities, and probably repre- 
sent the feeding work of newly emerged adults in the latter part of July. 

The well-known crescent-shaped scars (Plate XXIX, 117) resulting 
from the work of the ovipositing female during the latter part of June 
are generally recognized at picking time. The typical crescent has one 
straight side, at the middle of which there is a projecting point represent- 
ing the place where an egg was inserted. In many cases this distinctive 
egg mark does not show plainly, but an interruption of the straight margin 
at the middle can usually be distinguished. 

Mature scars from six varieties of apples are shown in Plate XXIX, 
117, in which the egg-puncture marks are seen in varying degrees of dis- 
tinctness, these apples representing skins of different colors and textures. 
The Twenty Ounce apple shown in Plate XXVIII, 114, indicates how 
several curculio crescents grouped together may resemble the scars made 
by case-bearers, but an examination of the individual scars shows clearly 
the distinctive egg-puncture marks made by the female when ovipositing. 

Perhaps the scars sometimes made by apple redbugs are the most likely 
to be confused with curculio work. An apple having scars of both 
curculio and redbugs is shown in Plate XXVIII, 115, for comparison. As 
pointed out above, however, there is little danger of confusing curculio 
feeding punctures with redbug work, for the distinctive egg crescents are 
invariably present on apples deformed by the curculio. 

A study of the late summer scars made by the curculio revealed the 
fact that brown rot often results in the wounds. As was shown in the 
case of late codling-moth work, certain large species of muscid flies may 
enlarge the scars and assist in the development of brown rot, and this the 
flies clean out as fast as decay takes place (Plate XXX, 120 and 121). 
When undisturbed by flies the feeding punctures made by the curculio 
during August will develop brown rot, this producing a dark ring about 
the point of injury (Plate XXIX, 116). 



Jnsec'is Affecting the Fruit of the Apple 485 

Freqiiently one finds that tough-skinned varieties, such as Ben Davis 
and Jonathan, when grown under the right conditions will exhibit warting 
of the curculio scars (Plate XXIX, 119). Here again the scars can 
usually be identified by the presence of the distinctive egg-puncture marks. 

The apple curculio 
(AntJioHomus quadrigibbiis Say) 

The common name of Anthonomus quadrigibbus would imply that it is 
primarily the curculio pest of the apple. It is not, however, as serious a 
pest on apples in ,New York as is the plum curculio. In certain localities 
A. quadrigibbus breeds abundantly on wild haws {Crataegus spp.), but in 
only a few instances was it discovered working on fruit in cultivated 
orchards. The apple curculio may be distinguished from the plum curculio 
by its long, curved rostrum, its elytra, broader toward the rear, and its 
four prominent humps (Plate XXX, 122). 

The apple curculio was found to be so scarce in orchards of western 
New York, that in order to study the injuries of this species on standard 
varieties of apples the writer collected a large number of the adults from 
hawthorn, and these were placed in cages with apples for experimental 
purposes. Forty pairs of the beetles were placed in as many tarlatan 
cages, each inclosing two or more young apples. Many of the young 
fruits were stung to death, but after June 15 many apples would cling 
when stung only two or three times. In order to prevent the fruits from 
being injured excessively, the cages, with the beetles, were moved to new 
fruits every two or three days. Several curculios continued to feed and 
lay eggs on the fruit until the middle of July, but after that date the 
beetles died off rapidly. 

As soon as the curculios were placed with the fruit they began feeding 
and laying eggs with unperturbed activity. In Plate XXX, 123 (photo- 
graphed on May 28) are shown two female curculios on a young apple, 
in which one of them is laying an egg. After depositing the egg the 
female turned about, closed the opening to the cavity with her rostrum, 
and then moved to the tops of the stamens to have a look at the surround- 
ings (Plate XXX, 124). The opening to both feeding and egg cavities 
appears merely as a rounded hole in the surface of the fruit. Through 
this opening the curculio thrusts its rostrum in order to excavate and eat 
the pulp, and frequently a rounded cavity is formed extending in all 
directions as far as the rostrum can reach (Plate XXX, 126). When 
excavating for purposes of oviposition only, the cavity may not be exca- 
vated so broadly. In order that the young grub may develop, the apple 
containing eggs must drop to the ground. Three or four stings on a fruit 



486 Bulletin 410 

will usually accomplish this result when there is competition among several 
fruits on one limb. After June 25, or when the apples have attained one- 
half an inch or more in diameter, many of the fruits will cling in spite 
of the punctures. No grubs were ever found to develop in the egg-laden 
apples that remained growing on the tree. Five Baldwin apples on which 
the ])eetles had fed and oviposited from June 25 to June 30. are shown in 
Plate XXX, 125, as they appeared when ready to drop on July 7; the 
punctures may be plainly seen, and the white exudation at the surface of 
some of them indicates that in those the young grub had ])egun activities. 

The work of two curculios on a Baldwin apple after July i is seen in 
Plate XXX, 126, the apple being shown in section to exi)ose the egg and 
feeding cavities. After July 4, very few apples, if any, that were in a 
strong growing condition when punctured, were found to drop and thus 
permit the grubs to develop. 

One experiment pertormed was that of caging a pair of beetles from 
June 16 to July 6 with two Baldwin apples which were on a limb made 
free of all other fruits. These apples were able to withstand the injuries 
of the curculios, and grew to maturity with the result shown in Plate 
XXXI, 127. Another good illustration of the mature scars resulting from 
injury by the curculio is presented in Plate XXXI. 128, showing two Stark 
apples. 

When growth of the fruit continues following the work of the beetles, 
the thin tissue and skin immediately above the egg or feeding cavity is 
found to dry out, usually leaving a white margin as shown in these two 
figures. A slight depression may result aljout the point of injury, due to 
the stoppage of growth, and the scar cavity itself always remains as a 
sunken brown spot. The most distinctive feature about the mature scar 
is the white-margined, dried-out tissue, resulting from the thin covering 
left immediately above the feeding or egg cavity. 

The apple curculio was found at work on Bartlett pears in one orchard, 
making cavities similar to those observed on apples. When beetles were 
caged with pears, typical feeding and egg laying took place. The mature 
scars resulting from this experiment are seen in Plate XXXI, 129. The 
cavities made by the apple curculio on pears were filled out to a certain 
extent by subsequent growth, a result somewhat different from that 
obtained on all the apples observed. 

TJic rose cJiafcr 

(Macrodacfylus subspiiiosits Fabricius) 

The adults of the rose chafer are general feeders, eating the fruit and 
the leaves of many kinds of cultivated and wild plants. The species 



Insects Affecting the Fruit of the Apple 487 

breeds in sandy pasture lands, where the grubs feed on the roots of 
grasses, and if orchards are located in the vicinity of such waste lands 
much injury may be done to the fruit when the beetles emerge and go 
forth in search of food and for mating. The writer had opportunity in 
1914 to study the result of an invasion of an apple orchard by rose chafers 
in Genesee County, New York. The beetles were first observed at work 
on the fruit about June 20, and they continued to feed and mate on the 
apples until July 4, at which time it became difficult to find them. The 
trees that suflfered the most were those bordering a sandy tract of pasture 
land, from which the insects evidently came to feed and to which they 
returned to lay eggs. 

The rose chafers were found to eat large, irregular holes in the young 
apples, the cavity frequently being so large that one or more beetles could 
conceal themselves in it. Typical feeding scars on Baldwin apples are 
shown in Plate XXXII, 130, in which one beetle may be seen at work. 
It was found that the chafers frequently return to the old wounds for 
feeding, evidently preferring to do this instead of starting on a fresh 
apple ; some beetles were observed to feed on wounds that were at least a 
week old. All fruits injured 1)_\" rose chafers were found to shrivel up 
and drop during July, and so no scars resulted on the fruit. A group of 
apples showing typical injuries is shown in Plate XXXII, 131, as photo- 
graphed on July 3 ; certain of these fruits were injured ten days previous 
to the time when the picture was made and appear greatly shriveled, while 
others, which were injured on a later date, indicate how the margin of 
the wound first shrinks and then curls inward, to be followed perhaps by 
brown rot. A few days later the same fruits would appear similar to the 
ones shown in Plate XXXII, 132, which have shriveled and dried out 
until they are scarcely recognizable. It is apparent that the irregular, 
rough wounds made by rose chafers feeding on apples are of such char- 
acter that healing is impossible, and sooner or later the injuries become 
infected with brown rot, eventually causing the fruits to shrivel and dry 
up. 

diptera 

Dipterous pests on the fruit of the apple are few in number, and only 
one species, the apple maggot, breeds in the fruit and causes economic 
losses. Ripe apples, and particularly summer varieties, are frequently 
damaged considerably by swarms of large muscid flies which sip at any 
point of rupture occurring on the surface of the fruit. Eventually large 
cavities are produced, and with the introduction of brown rot, decay of 
the apple is rapid. 



488 Bulletin 410 

The apple maggot 
(Rhagoletis pomoncUa Walsh) 

In New York the apple-maggot flies may appear in the trees early in 
July, and when late summer spraying is not practiced the flies soon begin 
niserting their eggs through the skin of the fruit (Plate XXXIII, 133). 
The &gg puncture appears as a tiny speck, and in those varieties whose 
growth is not yet completed, a small dimple may form about the point 
where the tgg was inserted (Plate XXXIII, 134). As soon as the apple 
begins to mellow, the tiny maggots begin to burrow through the pulp in 
all directions. The maggot works slowly until the apple softens in the 
ripening process, when it begins to grow rapidly, making winding tunnels 
through the pulp and quickly redticing the inside of the fruit to a brown 
pulp (Plate XXXIII, 135). In certain localities where the flies are uncon- 
trolled, the fruit of several summer varieties may be rendered entirely 
useless. 

Maiden Blush apples are grown for the market on a considerable scale 
in western New York, and in a few orchards, where late summer spraying 
for the codling moth was not done, the apple-maggot flies began to 
increase rapidly. A typical example of apple-'maggot work on this variety 
may be seen in Plate XXXIII, 135, photographed in section to show the 
extent of the tunneling by the maggots. The section on the right exhibits 
the emergence holes of the mature maggots, brown rot having developed 
about each tunnel and spread to destroy the whole fruit. A second apple 
cut in section (Plate X-XXIII, 136) illustrates more clearly the tunnels 
before the brown rot has reduced the pulp to a brown mass, and in this 
figure mature maggots may be seen as they appear when ready to emerge. 
Brown rot invariably develops in the maggot tunnels, and this condition 
appears to be very favorable for development of the maggots. 

The apple-maggot fly may lay eggs freely in standard varieties of apples 
when such apples occur where the flies have become numerous on more 
favorable fruit. But in such cases the maggots do not develop very 
rapidly until the ripening process has softened the pulp. The Tompkins 
King is a variety that becomes sufficiently mellow shortly after being 
picked to allow the maggots to complete development even after the fruit 
is packed in barrels. A Tompkins King apple which was bought in the 
market in October and which appeared to the average consumer as desir- 
able fruit, was packed away until the end of November, with the result 
shown in Plate XXXIV, 139. On November 29 some of the maggots 
had emerged, and brown rot could be seen as a discoloration on the sur- 
face, indicating that the inside of the apple was practically destroyed. 
Another Tompkins King apple, from which only two maggots emerged, 



Insects Affecting the Fruit of the Apple 489 

is shown in Plate XXXIV, 137. In this case so few maggots were at 
work that brown rot was much delayed in destroying the fruit. The 
photograph was made just four days after a maggot had emerged from 
the hole that is surrounded by brown rot. 

In Genesee County the writer found the apple maggot breeding freely 
in crab apples, a condition developing perhaps from the fact that in that 
locality this variety of fruit rarely, if ever, received the late summer sprays 
usually given the commercial orchards. In crab apples that are infested, 
dark tunnels may be seen just beneath the skin, and fruits that are cut 
in section exhibit typical work of the maggots (Plate XXXIV, 141). The 
crab apple is firm of flesh and very acid, and this prevents the maggots 
from making progress until the fruit has lain on the ground for two or 
three weeks. Crab apples drop freely from the tree and large numbers 
are usually permitted to remain on the ground to decay, and this condition 
promotes development of the apple maggot on this fruit. 

In some localities it may happen that the apple-maggot flies have 
developed in considerable numbers on early summer varieties of apples 
and a second brood emerges to oviposit during September. Either the 
flies of a second brood or the retarded members of a single brood may 
attack standard varieties of apples during late September, and the tiny 
punctures made by the ovipositor will appear as small, black specks from 
which few or no maggots develop. These spots may be identified by mak- 
ing a section through the puncture, which will usually reveal an egg or a 
tiny cavity where an egg had been placed. 

An interesting case of late oviposition by apple-maggot flies, perhaps 
the late oviposition work by individuals of a single brood, may be seen in 
Plate XXXIV, 140, showing a Baldwin apple photographed in October. 
The punctures made by the ovipositor were situated in small depressions, 
as is usual, but each incision was surrounded by a dark greenish color of 
unusual character. A pathological examination of the spots revealed the 
fact that both the black rot fungus (Physalospora Cydoniac) and the 
New England fruit spot (Phoma pomi) had entered and developed in the 
punctures, probably coming as an infection on the ovipositor of the female 
fly. The spots produced by stippen, a physiological condition, may some- 
times superficially resemble the oviposition marks of the apple-maggot 
fly, but with the aid of a hand lens one can always recognize the punctures 
made by the female ovipositor. 

hymenoptera 
Only two insects in the order Hymenoptera w^ere found affecting the 
fruit of the apple, and these are rarely present in sufficient numbers to 
cause economic losses. 



490 Bulletin 410 

TJic appJc-sccd chalcis 

(Syntomospis dnipaniin Boheman) 

The damage done by the tiny api)le-seed chalcis to the fruit, slight as it 
may be, is caused by the female when she inserts her long ovipositor 
through the pulp in an effort to reach the seeds. The work of the seed 
chalcis is found only on crab apples and Lady apples, for these are the 
only cultivated apples that are sufficiently small to permit the female to 
oviposit in the seeds. The female chalcis is interested merely in placing 
her egg in the apple seed, where the maggot will develop and remain to 
pass the winter. The puncture made by the ovipositor leaves a mark on 
the surface of the apple (Plate XXXIV, 138) which strongly resembles 
the oviposition scars produced by the apple-maggot fly. Both the apple- 
seed chalcis and the apple-maggot fly may work on the same fruits, but 
the individual punctures of the two species are distinguishable by a care- 
ful examination of the wound. If the scar is that of the apple-seed 
chalcis, a section through the puncture to the core will show a slight dis- 
coloration and scar along the path followed by the ovipositor (Plate 
XXXIV, 142). On mature fruits the work of the chalcis fiy may other- 
wise be identified by an examination of the apple seeds, which will show 
the presence of the larvae. Frecjuently it may happen that the apple-seed 
chalcis may breed and hecome so abundant that crab apples are much 
stunted and disfigured through the numerous wounds produced by exces- 
sive oviposition. 

The dock falsc-zvonn 

(Aiiictasfcf/ia glahrata Fallen) 

A rather unusual type of injury to mature fruit on the tree has been 
lecorded in Canada as the work of a sawfly larva, Ametastcgia glahrata 
Fallen. In the fall of the year the mature larvae desert their wild food 
plant and go in search of suitable hibernation quarters. When this insect 
occurs near the apple orchards it may so happen that the larvae will climb 
up the trees and eat holes in the fruit, excavating cells just large enough to 
make comfortable hibernation quarters. The writer found an example of 
this peculiar injury at Ithaca, New York, and a photograph of the sawfly 
larva in its cell is shown in Plate XXXV, 143. The larva excavates a 
hole in the flesh of the apple, in depth slightly greater than its own length, 
thus forming a cell, the opening being closed by bits of the excavated pulp. 
This insect "will probably never cause trouble in well-kept and cultivated 
orchards. 



Insects Affecting the Fruit of the Apple 491 

INJURIES TO THE FRUIT OF THE APPLE BY AGENCIES OTHER THAN 

INSECTS 

The preceding part of this paper deals with specific types of injuries 
caused by insects, but the person who has occasion to grade or to inspect 
apples will meet with many other peculiar and little-known scars. In 
order to recognize all scars arising from insect activities, it was necessary 
to take into consideration all types of injury that may be found on the 
fruit. The more important and more frequently met types of injury 
caused by agencies other than insects, are discussed in the following pages. 

WARTING OF SCARS 

The peculiar phenomenon exhibited by scars that bulge out beyond the 
normal surface of the fruit has been designated as zvartimj of the scars. 
The writer has seen this warting produced in scars made by redbugs 
(Plate XXXV, 144 and 145), by curculios (Plate XXIX, 119), by fruit- 
tree leaf rollers, by green fruit worms, by tussock moths (Plates XXI, 
83 and 84, and XXXV, 146), by apple scab, and by frost injury (Plate 
XL, 168). It is apparently because of unusual growing conditions that 
the injuries caused by these several agencies produce the abnormal bulging 
growth under the scar. This warting of the scars produces peculiar 
results in some cases (Plate XXXV, 146), and may be explained by 
accelerated growth late in the season. After the middle of August, apples 
usually grow very slowly, but occasionally favorable rains after that date 
force new and rapid growth. \\'hen growth is accelerated in the fruit, it 
is apparent that considerable pressure is exerted on the old and more or 
less hardened skin. Scar tissue when present, being the most recentlv 
formed and tender, gives way first, and new cells are formed beneath the 
area. In tough-skinned apples such as the Ben Davis (Plate XXXV, 
146), the new growth is forced the most completely through the newly 
formed 'scar tissues. 

MECHANICAL INJURIES 

Apples frequently become scarred by rubbing against limbs and by 
striking stubs or .sharp limb ends. In Plate XXXVI, 147, is shown a 
Rhode Island Greeuing apple which was rubbed constantly by a limb iust 
underneath, from the time it was an inch in diameter until picking time. 
The russet area is covered with checkered spots of thickened brown corky 
tissue, all of which was highly polished by the rul)l)ing limb. A Baldwin 
apple which was blown frequently against a sharp stub is shown in Plate 
XXXVI, 148. The efifect in this case was that holes were punched in the 
skin of the fruit. A very similar example, only that the punctures were 
made b\' a very sharp stub, is shown in Plate XXXVI, 149. Some of the 



492 ' Bulletin 410 

early wounds healed much as do the scars produced by redbugs, but the 
later injuries produced a different scar. When the fruit rubs against a 
limb and there are no sharp points to break the skin, a rough russet sur- 
face may be produced on the skin. In another case observed, a Baldwin 
apple rubbed against a stub from the time it was one-half inch in diameter 
until it had grown to be one and one-half inches in diameter, when the 
obstruction was removed. The mature scar (Plate XXXVI, 150) 
resembled somewhat the scars resulting from slight injury by lime-sulfur 
spray, but the russet surface was more restricted to a definite area on one 
side of the fruit than would have been the case with spray burn. 

EXPERIMENTS IN PRODUCING SCARS BY PIN PUNCTURES 

The peculiar spreading scars that develop on apples injured by feeding 
redbugs led the writer to experiment on the fruit with fine pin punctures, 
to ascertain whether the mechanical punctures alone would produce the 
same type of scar. 

In making feeding punctures, Lygidca incndax may inject into the 
wound a poison which affects the fruit diff'erently from ordinary punc- 
tures. The peculiar festering noted in the wounds made by feeding red- 
bugs, and their subsequent development, are so characteristic that it seems 
very probable that some secretion of the bug plays an important part. The 
writer made dissections of nymph and adult heads of L. mendax in an 
effort to locate poison glands, but if such were present they were so small 
that he failed to find them. 

The bug when feeding will at intervals raise and lower its proboscis in 
the wound, evidently lacerating the pulp cells in order to obtain a greater 
flow of sap. Experiments in imitating redbug wounds were made by 
using a No. o insect pin to make the punctures. On June 7, when the 
young apples were not more than a half inch in diameter, a large number 
of fruits were treated in this way. The mature result of some of these 
pin punctures on a Rhode Island Greening apple is shown in Plate 
XXXVI, 151. The pin punctures did not produce a characteristic festered 
wound such as is made by redbugs, with the subsequent splitting of the 
adjacent skin and development of russet scars. 

CRACKING FRUIT 

One frequently finds apples that are circumscribed by large and exten- 
sive cracks, and in most cases these appear to be the result of steady 
growth. In all cases it would appear that cracks on the surface of the 
fruit are due to a hardening of the skin before the normal size of the 
apple is attained. When the skin loses its ability to expand and take care 
of the increase of size required by growth, the natural result is the forma- 



Insects Affecting the Fkuit of the Apple 493 

tion of cracks on the surface to permit of the necessary increase in size 
due to growth pressure within. The Roxhury is an apple which frequently 
exhibits cracks, and this might be expected, due to the unusual type of skin 
that this variety possesses (Plates XXXVI, 152, and XXXVII, 153). 
Certain fruits that have been excessively scarred by insects may develop 
cracks in the dry, hard skin as a. result of expansion by later growth. 
Two Rhode Island Greening apples which were largely covered by the 
broad russet scars resulting from redljug injury, developed cracks as 
shown in Plate XXXVII, 154, photographed in August. An interesting 
example of the habitual development of large, broad surface cracks was 
to be found on a Baldwin tree, one large limb of which always produced 
fruit with a thick russet skin and broad cracks (Plate XXXVII, 157). 
That part of the tree which produced these strange russet apples, so unlike 
the typical Baldwin apples that grew on other parts of the tree, was evi- 
dently a sport development and always produced fruit with a thick^ tough 
skin that must necessarily crack during growth. 

LIME-SULFUR SPRAY INJURY 

Lime-sulfur spray as ordinarily used — t to 40 — will, if the young 
fruit is drenched, cause slight burning, but the extent of injury depends 
much on the variety affected. The Tompkins King apple is particularly 
tender, and it is this variety that shows oftenest the effects of spray injury 
(Plate XXXVm, 158). In many cases the injury results in russet scars 
which in some' respects may resemble the work of redbugs. In Plate 
XXXVII, 156, is shown a perfectly shaped Baldwin apple which has 
typical russet scars produced by slight burning from lime-sulfur at the 
time of the calyx spray. This type of scar may usually be recognized by 
the many fine and irregularly placed russet streaks and cracks. 

SUN-SCALD 

Sun-scald is the name usually ap])lied to the excessive burns that may 
result from late summer spraying when the sunshine is bright and the 
atmospheric temperature high. A good illustration of this was observed 
in 1914, when spraying was done on August 4 and August 5 for the second 
brood of codling moth. On both days the sunshine was ver\' hot and the 
temperature ranged from 90^ to 100^ F. All apples that were well 
covered with the spray and then exposed to the sunshine fo'r three or four 
hours developed a characteristic burn. Four days later, or on August 
9, the results of the sun-scald attracted attention. Two Rhode Island 
Greening apples as picked are shown in Plate XXX\TII, 160; the dark 
color of the scalded spots shows through the coating of arsenate of lead 
and lime-sulfur. In the case of Baldwin apples that developed sun-scald, 
the dark scalded area showed clearly in contrast with the red color of the 



494 Bulletin 410 

fruit. The cells beneath the scalded spots were killed to a depth of from 
one-eighth to one- fourth inch, and turned dark brown within four days 
after the burn occurred. A section through a scald spot on a Baldwin 
apple, which was typical of the average burn, shows the brown color pene- 
trating to not more than one-eighth inch (Plate XXXVIII, 159). One 
of the same Baldwin apples is shown in Plate XXXVIII, 161, with a 
mature scald scar as it appeared on October 21. The burned tissue turned 
brown and dried out, only to be followed later l)y the formation of large 
cracks in the dead tissue. 

SCARS PRODUCED BY FROST INJURY 

The writer observed that frost injury to young apples may develop into 
scars that very much resemble the large russet scars made by redbugs. 
The spring of 191 5 was a season when frost was neted in many localities 
in western ,New York. A frost occurred on the morning of May 28, 
which was soon after the young apples had set. The apples that recovered 
from the injury developed a characteristic scar band, usually extending 
around the middle of the fruit but in some cases appearing either nearer 
the base or toward the calyx (Plates XXXIX, 167, and XL, 171). The 
first apples observed to be recovering and exhibiting effects of freezing 
were found on June. 16 (Plate XXXVIII, 162). The apples that were 
killed by the frost were dropping off rapidly on the same date. Many 
orchards that were situated in valleys had all the fruit killed, while other 
orchards, located on hillsides, had only part of the fruit killed. In some 
places it was possible to locate within a few inches the highest point that 
the frost level reached. In such orchards one could find fruits exhibiting 
all stages of freezing, which were indicated later by corresponding scars 
on the apples that recovered. A Northern Spy apple from an orchard in 
which nearly every apple was killed is shown in Plate XXXIX, 163 ; prac- 
tically the whole surface is covered with russet, and during later stages of 
growth several large cracks occurred in the skin. 

Scars resulting from frost injury can usually be recognized by the 
splitting of the skin along the axis of the fruit, which makes the scar 
band uneven (Plate XL, 168 and 169). Many fruits, however, exhibit 
practically a continuous band of russet which corresponds to the surface 
diat was frosted on the young apple. The location of the band has much 
to do with the growth of the apple and its shape at maturity (Plate 
XXXIX, 166 and 167). Certain apples were only slightly frosted, and 
in these cases the scars appeared in only two or three places around the 
circumference of the fruit. In such fruits the scars were sometimes dififi- 
cult to distinguish from the injuries produced by redbugs. Isolated frost 
scars always appear as splits along the axis of the fruit (Plate XL, 168), 



Insects Affecting the Fruit of the Apple 495 

while the scars produced by redhugs are very irregular and extend in all 
directions. Frecjuently the splits occurring along the axis of the fruit are 
reduced to four or live in number and are grouped at one end (Plate XL, 
169). The seeds were always killed in badly frosted apples, and many 
apples that grew to large size exhibiting frost bands were found to con- 
tain only one or two seeds. Frost bands were even distinguishable on the 
surface of russet apples. In Plate XL, 170, three Golden Russet apples 
are shown with typical frost bands and cracks, the extent of which may be 
readily recognized on the normal russet surface. 

In those orchards where the frost was most severe and all the fruit was 
apparently frozen, it was possible to find clusters of stunted, russet-cov- 
ered apples wherever the rosy aphid had developed and was present. on the 
cluster at the time when the frost occurred. These fruits were worth- 
less, but were of interest as indicating the influence the aphids had in 
causing the frozen fruit to cling through the growing season. 

HAILSTONE INJURY 

The scars resulting from hailstone injury may assume various shapes 
and forms. On isolated fruits such scars are in some cases dilBcult to 
distinguish from certain insect scars. If the hailstone injury occurs early 
in the season," while the fruit is growing rapidly, many of the apples will 
recover and exhibit scars that resemble somewhat the work of tussock- 
moth larvae or the very early intermittent feeding of the green fruit 
worms. An apple having four hailstone scars which were inflicted early in 
July, and one small scar produced by a green fruit worm in June, is shown 
in Plate XLI, 176 (photographed on August 23). The hailstone scars 
invariably exhibit a considerable amount of dead, corklike tissue resulting 
from the drying-up of the injured cells. In the case of Baldwin apples 
observed, which were injured by hail on July 20 and examined on Septem- 
ber 25, the bruised cells were found to turn brown, dry out, and then 
crack and fall away. Usually some of the corklike cells are left clinging 
to the inside of the pit. 

A Baldwin apple that was injured on July 20 is shown in Plate XLI, 
173, as photographed on August 4; deep-sunkeii pits were produced, and 
the cells immediately beneath the scars turned brown and tlried out. Sec- 
tions at two different Icxels ininiecHatelv benealli such spots are shown in 
Plate XL, 172, indicating the depth of the wound and the way the tissue 
dries out. A Baldwin apple which was injured by a large angular hail- 
stone is seen in IMate XLI, 174. Haldwin apples severely injured by had 
on July 20, , exhil)iting large, angular scars more or less filled with the 
dead and dried-out tissue, are shown in Plate XLI, 175 and 178, in the 



496 Bulletin 410 

stage of recovery that was attained by August 17. Even crab apples, 
small as they are, may show the same type of ugly wounds due to hail- 
stone injury as are found on tlie standard \arieties of apples (Plate 
XLI, 177). 

APPLE SCAB 

Apple scab causes much injury to apples even in orchards that are well 
sprayed, and is a factor that often enters into combination with other 
scars to disfigure the fruit. Typical scab spots usually exhibit a char- 
acteristic papery edge around the margin of the scar, which represents the 
cuticle of the skin that is left by the fungus (Plate XLII, 179). After a 
time the scab spots may lose this character and appear as dark-colored, 
irregular blotches. Late scab infection occurring during early September, 
may cause red color to develop around the point of infection, thus giving a 
superficial reseniblance to San Jose scale ( Plate XII, 37) . Very soon, how- 
ever, the scab spots grow larger and acquire a characteristic dark color 
'at the center (Plate XLII, 181). The old scab scars may become smooth 
and even russet-colored by the time the fruit is matured, and when con- 
ditions are right for producing growth late in summer, warting of the 
scars may take place. An excessive amount of scab grouped on one side 
of the apple may dry out the surface to such an extent that large cracks 
will appear (Plate XLII, 180). 

STIPPEN 

Large and over-grown Baldwin apples may frequently exhibit small, 
discolored spots, somewhat resembling the spots from which scale insects 
have been removed. Such imperfections are caused by a physiological 
disease known as stippen. When a stippen spot occurs in connection with 
an enlarged lenticel of the skin, it may be somewhat suggestive of an 
oviposition mark made by the apple-maggot fly. A section through such 
spots, however, will reveal the true cause. Stippen may be recognized in 
section by the numerous brown discolorations caused by the dying and 
Jrying-out of groups of cells throughout the flesh of the fruit, and par- 
ticularly at the surface (Plate XLII, 182). 

ACKNOWLEDGMENTS 

To Professor Glenn W. Herrick, under whose direction this problem 
was studied, the writer is greatly indebted for many helpful suggestions 
and criticisms during the progress of the work, and more recently in the 
final preparation of this paper. 

The writer is indebted also to Dr. William T. M. Forbes for the deter- 
mination of certain species of Lepidoptera. and to Dr. L. R. Hesler for 
the determination of fungi found developing in the fruit. 



Insects Affecting the Fruit of the Apple 497 

BIBLIOGRAPHY 

(Altl ough the writer has not attempted to (hscuss anything in this 
thesis beyond his own observations, the following bibliography is appended 
in order to give one or two of the more important references to each insect 
discussed, or references having special bearing on the work in New 
York.) 

BuscK, August. Marmara pomonella n. sp. In Descriptions of new- 
North American Microlepidoptera. Ent. Soc. Wash. Proc. 17 : 89. 
1915. 

Crandall, Charles S. The curculio and the apple. Illinois Agr. Exp. 
Sta. Bui. 98:465-560. 1905. 

Crawford, H. G. A capsid attacking apples. Ent. Soc. Ontario. Rept. 
46(1915) : 79-88. 1916. 

Crosby, Cyrus R. On certain seed-infesting chalcis-flies. Cornell Univ. 
Agr. Exp. Sta. Bui. 265 : 365-388. 1909. 

The apple redbugs. Cornell Univ. Agr. Exp. Sta. Bui. 291 : 211- 



226. 1911. 

Felt, Ephraim Porter. Fall webworm (Hyphantria textor Harris). 
/;; Forest insects, i : 142-146. 1905. 

Foster, S. W., and Jones, P. R. Additional observations on the lesser 
apple worm. U. S. Ent. Bur. Bui. 80^: 45-50. 1909. 

Gibson, Arthur. The dock sawfly (Ainctasfcgia glabrafa Fallen). In 
Reports on insects of the year. Ent. Soc. Ontario. Rept. 46(1915) : 
13-14. 1916. 

Hammar, a. G. The cigar case-bearer. U. S. Ent. Bur, Bui. 80^: 33- 
44. 1909. 

Life history of the codling moth in northwestern Pennsylvania. 



U. S. Ent. Bur. Bui. 80®: 71-111. 1910. 

Hartzell, Frederick Z. The rose-chafer. In A preliminarv report on 
grape insects. New York (Geneva) Agr. Exp. Sta. Bui. 331 : 530-549. 
1910. 

Herrick, Glenn W. The fruit-tree leaf -roller. Cornell Univ. Agr. 
Exp. Sta. Bui. 311:277-292. 1912. 

Herrick, Glenn W., and Leiby, R. W. The fruit-tree leaf roller. Cor- 
nell Univ. Agr. Exp. Sta. Bui. 367: 245-280. 1915. 

Hov^ard, L. O. a peculiar damage to the apple. In Some miscellaneous 
results of the work of the Division of Entomology. U. S. Ent. Div. 
Bui. 10, n.s. : 87-88. 1898. 
(Referred to by Busck, 191 5.) 



498 Bulletin 410 

Illingwortii, James F. A study of the biology of the apple maggot 
(Rhagolctis pomonclla), together with an investigation of methods of 
control. Cornell Univ. Agr. Exp. Sta. Bui. 324: 125-188. 1912. 

Lowe, V. H. The pistol-case-bearer. New^ York (Geneva) Agr. Exp. 
Sta. Bui. 122:219-232. 1897. 

Marlatt, C. L. The San Jose or Chinese scale. U. S. Ent. J3ur. Bui. 
62:1-89. 1906. 

Newcomer, E. J. The dock false-worm: an apple pest. U. S. Agr. Dept. 
Bui. 265 : 1-40. 191 6. 

Parrott, p. J., HoDGKiss, Ji. E., AND Lathrop, F. H. Plant lice in- 
jurious to apple orchards. I. Studies on control of newly-hatched 
aphides. New York (Geneva) Agr. Exp. Sta. Bui. 415: 11-53. 1916. 

Quaintance, a. L. The aphides affecting the apple. U. S. Ent. Bur. 
Circ. 81 : i-io. 1907. 

The lesser apple worm. U. S. Ent. Bur. Bui. 68^ : 49-60. 1908. 

Quaintance, A. L., and Jenne, E. L, The plum curculio. U. S. Ent. 
Bur. Bui. 103:1-250. 1912. 

Schoene, W. J. The tussock moth in orchards. New York (Geneva) 
Agr. Exp, Sta. Bui. 312 : 39-49. 1909. 

Slingerland, Mark Vernon. The bud moth. Cornell Univ. Agr. Exp. 
Sta. Bui. 50:1-29. 1893. 

The cigar-case-bearer in western New York. Cornell Univ. Agr. 



Exp. Sta. Bui. 93:211-230. 1895 a. 

Climbing cutworms in western New York. Cornell Univ. Agr. 



Exp. Sta. Bui. 104:551-602. 1895 b. 
The bud moth. In Wireworms and the bud moth. Cornell Univ. 



Agr. Exp. Sta. Bui. 107:57-66. 1896 a. 

Green fruit worms. Cornell Univ. Agr. Exp. Sta. Bui. 123 



505-522. 1896 b. 
The pistol-case-bearer in western New York. Cornell Univ. 



Agr. Exp. Sta. Bui. 124: 1-17. 1897. 

The codling-moth. Cornell Univ. Agr. Exp. Sta. Bui. 142:1-69. 



1 898. 



The palmer-worm. Cornell Univ. Agr. Exp. Sta. Bui. 187:77- 

loi. 1901. 

Notes on the red-banded leaf -roller (Eulia trifcrana Walk.) 



that sometimes works with the grape-berry moth. In The grape-berry 
moth. Cornell Univ. Agr. Exp. Sta. Bui. 223 : 59-60. ' 1904. 

Slingerland, Mark Vernon, and Crosby, Cyrus Richard. Manual 
of fruit insects, p. 1-503. 1914. 




^ s 






Plate IV 

INJURIES PRODUCED BY LYGIDEA MENDAX 

1, Rhode Island Greening apples with nymph and adult redbugs, showing the injuries they 
produce, l^hotagraphed on June i8 

2, Redbug injuries on Northern Spy apple. The scars are spreading and joining one 
puncture witli another. Photograiihed on July 8 

3, Northern Spy apple showing mature scars which on July 8 were very similar to those 
shown in figure 2. Photographed on September 22 

4, Rhode Island Greening apple (at left) and Tolman apple (at right), showing typical 
deeply pitted redbug injuries on the mature fruit. Photographed on October 21 



BuixETiisr 410 



Plate IV 




Plate Y 
injuries produced by lygidea mendax 

5, Baldwin apples showing the beginning of russet scars, the punctures having been made 
from seven to ten daj'S earlier by the feeding redbugs. Photographed on June 24 

6, Baldwin apples showing the development of russet scars on July 3, practically two 
weeks after the punctures were made by the feeding redbugs 

7, Roxbury apples in section, showing the condition of the tissue surrounding points of 
puncture made by redbugs in June. Photographed on August 30 

8, Northern Spy apple showing the deep pits resulting where redbugs fed on the fruit 
and made punctures that reached the core. Photographed on August 25 

9, Mature Rhode Island Greening apple showing a few deep pits resulting from redbug 
j)unctures which are very suggestive of plum curculio work 



Bulletin 410 



Plate V 




Plate \'l 

INJURIES PRODUCED BY LVGIDEA MENDAX 

10, Maiden I'.lush apple showing the scars resulting from the feeding of adult redbugs. 
Photographed on September 20 

11, Tolman apple showing the mature scars resulting from feeding punctures of adult 
redbugs. Photograjihed on October 2^ 

12, Mature Northern Spy api:.le illustrating the result when redbug punctures that have 
reached the core tissue occur along one or two definite lin^s 

13, St. Lawrence apple on which the russet type of redbug scar changes to smooth, brassy, 
russet-colored scars. Photograjihed on July 2S 

14, Rhode Island Greening apple photographed on July 7, showing character of scars on 
that date 

15, Golden Russet apples showing deep pits and russet scars caused by redbugs. Photo- 
graphed on July 13 

16, \\'ork of redbugs on natural fruit, exhibiting all tvpes of scars. Photographed on 
July 6 



Bulletin 410 



Plate VI 




■»«£i*KrJiCn-.*J 



Plate VII 

INJURIES PRODUCED RY LYGIDEA MENDAX AND BY APPLE SCAB 

17, Rhode Island Greening apples showing an early stage of redbug scars, photographed on 
July 7 for comparison with apple scab spots shown in figure i8 

1 8, Apple scab spots photographed on July 7 and shown for comparison with redbug scars 

19, Roxbury apples showing both the pitted and the russet type of scars, the russet scars 
being little different from the natural skin of the fruit 

20, Mature russet scars caused by feeding redbugs on an unnamed variety of apple hav- 
ing a polished, light-colored skin. Photographed on September 25 

21, Baldwin apple which was badly injured by feeding redbugs in June but recovered 
and grew to maturity exhibiting russet scars. The remains of a young apple that was killed 
by the feeding bugs may be seen 



Bulletin 410 



P-LATE VII 




Plate VIII 

INJURIES PRODUCED BY LYGIDEA MENDAX AND BY APHIS SORBI 

22, Baldwin apjile, perfect in shape but showing the more or less smooth, russet type of 
redbug scars. Photographed on Septemb r 27 

23, Roxbury apiile punctured by feeding redbug nymphs in June. This developed into 
a perfectly shaped fruit, but it exhibits russet scars which show in contrast with the natural 
russet color of the fruit. Photographed on September 7 

24, Baldwin fruits that were severely injured by feeding redbugs, followed by an infesta- 
tion of Aphis sorbi. Such wounds become enlarged by the action of the aphid, exhil)i'ting a 
frothy exudation and an enlargement of the scar by the splitting of the skin at certain points. 
Photographed on June 25 

25, Rhode Island Greening apples photographed on September 21, which on June 25 were 
in a very similar condition to the fruits shown in figure 24, fruits that were first punctured 
by redbugs and then suffered from an infestation of Aphis sorbi 



Bulletin 410 



P'LATE VIII 




23 



Plate IX 

INJURIES PRODUCED BY LYGIDEA MENDAX, HETERCCORDYLUS MALINUS, AND APHIS SORBI 

26, Heterocordylns malimis. A female bug, heavy with eggs, feeding on a young apple. 
Photographed on June 18 

27, Mature quinces photographed on September 18, sliowing the scars resulting from the 
feeding of redbug nymphs of Lygidea mendax in June 

28, A Twenty Ounce apple, and a slice from a second fruit, which show the mature scars 
caused by redbugs. In all )^robability this is the work of Heterocordylns malinus 

29, A cluster of six Baldwin apples, photographed on June 24, showing typical work of 
Aphis sorbi at that date 



Bulletin 410 



Plate IX 




Plate X 



INJURIES PRODUCED I!Y APHIS SORBI 



30, A cluster of six Baldwin apples which wsfre infested by Aphis sorbi in June and 
photographed on the tree on July 4 

31, The same cluster of apples as is shown in figure 30, as they appeared at the end of 
the growing season. Photographed on September 25 (nearly natural size) 



Bulletin 410 



P'late X 




Plate XI 

INJURIES PRODUCED BY APHIS SORBI AND BY A. POMl 

32, Pippin apples showing a puckered appearance at the stem end, or base of the fruit, 
a condition usually seen only at the calyx end and resulting from an infestation of Aphis sorhi 

33, A cluster of Baldwin apples which were first infested with Aphis sorhi, followed by 
Aphis pomi during the period between June 25 and July 20. The dark, smutty appearance 
results from the work of a fungus on the honeydew secreted by Aphis pomi. Photographed 
on August 4 

34, Apples showing the black, smutty appearance that results from the development of 
a fungus on the honeydew secreted by Aphis pomi. Photographed on August 4 



Bulletin 410 



Plate XI 




Plate XII 

INJURIES PRODUCED BY ASPIDIOTUS PERNICIOSUS, APPLE SCAB, AND CARPOCAPSA 

POMONELLA 

35, Baldwin apple which shows a heavy infestation of San Jose scale on the calyx end of 
the fruit. Photographed on November 29 

36, Mann apple showing the characteristic development of red color about the scales. 
Photographed on November jg 

37, Maiden Blush apples which developed late scab infections and show color about the 
scab spots, superficially resembling the spots made by San Jose scale. Photographed on 
September 18 

38, Baldwin apple cut in section, showing a mature codling-moth larva in its burrow. 
Photographed on July 8 

39, Rhode Island Greening apple in section, showing a typical burrow and the nearly 
full-grown codling-moth larva. Photographed on August 4 



i 



Bulletin 410 



Plate XII 




Plate XIII 

INJURIES PRODUCED BY CARPOCAPSA POMONELLA 

40, Apples spread apart to show the work of codling-moth larvae where the fruits rested 
in contact. Photographed on July 28 , „ , 

41, Fall Pippin apple showing the work of second-brood larvae during September. Each 
white frothy spot indicates where a larva was trying to enter the fruit. Photographed on 
September 18 , , 1 , • , 

42, Slices from apples that show " side-worm " injury produced by late-appearing larvae 
of the first brood. The larvae were poisoned, but did not die before making a small hole in 
the fruit. Color develops around the spots much as it does around scale insects. Photographed 
on August 4 






I 



Bulletin 410 



Plate XIII 




4^^ 



Plate XIV 

INJURIES PRODUCED BY CARPOCAPSA POMONELLA AND BY ENARMONIA PRUNIVORA 

43, Rhode Island Greening apple showing two larval exit holes, indicating that two 
codling-moth larvae had developed in the fruit. Photographed on September 26 

44, The apple shown in figure 43, in section, exhibiting the two larval burrows. Brown 
rot may be seen developing along the right-hand biirrow 

45, Baldwin apple showing the work of Pollenia and other muscid flies, which frequently 
enlarge the "side-worm" holes made by codling-moth larvae. Photographed' on September 3 

46, Baldwin apple showing the white frothy spot where a late-appearing codling-moth larva 
of the first brood entered into the scar cavity made by a leaf-roller larva. Photographed on 
July 20 

47, Slices from apples showing " side-worm " injuries produced by second-brood codling- 
moth larvae in September. The larvae were dead except in the left-hand slice, which shows 
a white exudation from the spot. Photographed on September 9 

48, Sections of apple showing (at right) the surface work of the larva of Enarmonia 
prunivora in an apple, and (at left) the tunnels just beneath leading to the core. Photographed 
on September 9 



BULLETIX 410 



Plate XIV 




Plate XV 

INJURIES PRODUCED BY ARCHIPS ARGYROSPILA 

49, Work of a leaf-roller larva in destroying a fruit cluster, showing how the leaves and 
the young fruits are webbed together. Photographed on June 9 

50, A leaf-roller larva protruding from its rolled leaf retreat, and the apple next to 
it on which the larva fed. Photographed on June 9 

51, Rhode Island Greening apples showing types of fresh scars made by leaf-roller 
larvae. Photographed on June 24 

52, Additional fruits that show typical leaf-roller scars found on June 24 

53, Pippin apples showing deep and narrow scars. These fruits had part of their cores 
eaten out, but were able to recover and grow to maturity. Photographed on September 19 

54, Twenty Ounce apples that show deep cavities made by feeding larvae. Two of these 
apples were recovering, while the specimen in the center had succumbed to the injuries 
received. Photographed on July 8 



Bulletin 410 



Plate XV 




Plate XVI 

INJURIES PRCDUCED EV ARCHIPS ARGYRCSPILA AND BY XYLINA ANTENNATA 

55, Apples showing scars ir.ade by lerf-roller larvae. Photographed on July 7 

56, Apples showing scars made by Xylina antennata, to be compared with the work of 
the leaf-roller larvae shown in figure 55. Photographed on July 7 

57, Baldwin apples exhibiting deep scars made by leaf-roller larvae. Photographed on 
August 30 

58, Twenty Ounce ai)ple showing how the deep cavity made by a leaf roller has grown out 
and nearly filled the original cavity. Photographed on October 21 

59, Roxbury apple showing a small, shallow scar made by the late feeding of a leaf-roller 
larva. The large crack which encircles the apple was caused by growth pressure after the skin 
of the fruit had become hardened 



Bulletin 410 



F'LATE XVI 




Plate XVII 

INJURIES PRODUCED BY XYLINA ANTENNATA 

60, Comparison between the injury made by a leaf-roller larva (left) and the feeding: 
work on young apples of a green fruit worm (right). Photographed on June 12 

61, Nearly full-grown larva of Xylina antennata, feeding, with its head in a young apple. 
Photographed on June u 

62, Scars made by a fruit worm on June 20, photographed on June 24 after the wounds 
have turned brown. These fruits have just attained the size which would enable them to recover 
from shallow wounds such as are shown 

63, Apples showing scars made by fruit worms on June 18, photographed on June 24 
when the scar tissue was just beginning to form 

64, Apples photographed on June 24, showing scars produced by young fruit-worm larvae 
about June 8 to .June 10. The scars were so small that the fruits were recovering 

65, Bartlett pears showing mature scars caused by the feeding of one fruit-worm larva in 
June. Photographed on September 9 



Bulletin 410 



Platk X\'II 




■ 'Plate XVIII 

INJURIES PRODUCED I!Y XYLINA ANTENNATA 

66, Rhode Island Greening apple showing mature scars produced by the intermittent feeding 
of fruit-worm larvae at a time when the fruit was not more than half an inch in diameter. 
Photographed on August 14 

67, Pippin apple showing excessive injury by a fruit-worm larva, the apple, ho.vever, con- 
tinuing to grow. Photograiihed on November i 

68, Baldwin apple, natural size, showing that the core was reached by a feeding fruit-worm 
larva, and yet the fruit recovered and grew to maturity. Photographed on November i 

69, Tompkins King apple showing a large fruit-worm scar, this case being unusual in that 
two scars joined to form one large irregular one. Photograjhid on September 9 

70, Baldwin apples showing typical broad fruit-worm scars. Photographed on August 2^ 



Bulletin 410 



Plate XVIII 




Plate XIX 

INJURIES PRODUCED BY XYLINA LATICINEREA, RHYNCHAGROTIS PLACIDA, AND HEMERO- 

CAMPA LEUCOSTIGMA 

71, A larva of Xylina laticinerca, nearly full-grown, and four young apples on which it had 
been feeding. Photographed on June 18 

72, Rhode Island Greening apple on which a larva of Rhynchagrotis placida fed from 
June 16 to June 19. Picked and i)hotographed on August 16 

73, Baldwin apple showing mature scars produced by a larva of Rhynchagrotis placida feed- 
ing on the young fruit in June. Photograjihed on September 21 

74, Rhode Island Greening apples showing two tussock-moth larvae at work, and the typical 
scars, on June 24. The small apple at the right had received excessive injury, which would 
result in its early dropping 



Bulletin 410 



Plate XIX 




Plate XX 

INJURIES PRODUCED BY HEMEROCAMPA LEUCOSTIGMA 

75, Work of one tussock-moth larva on a Rhode Island Greening apple. The larva was 
found at work on the apple on June 29, and it continued to feed until it was photographed on 
July 3 

76, Baldwin apples which were recovering from injury, each apple showing several of the 
small, shallow scars that are characteristic of tussock-moth work. Photographed on July 4 

77, Twenty Ounce apple showing the typical scars that result from tussock-moth work. 
Photographed on August 30 

78, Rhode Island Greening apple showing the large, shallow scars, with irregular margins, 
characteristic of large scars made by the tussock-moth larva. Photographed on September 22 

79, Northern Spj' apples showing the long, slender feeding channels of the larva, th-'s 
being a characteristic injury after the skin of the fruit has become hardened. Photographed 
on July 20 

80, Twenty Ounce apple showing a scar that did not heal perfectly, due to the fact that 
the injury was received after active growth had stopped. Photographed on August 30 



Plate XX 




Plate XXI 

INJURIES PRODUCED BY HEMEROCAMPA LEUCOSTIGMA AND BY YPSOLCPHUS LIGULELLUS 

8i, Rhode Island Greening apple showing a very large and unusual tussock-moth scar, the 
wound having occurred in mid-July at a time when growth was so slow that brown rot might 
well have resulted. Photogra[)hed on October 2i 

82, Late tussock-moth work showing excessive feeding on one apple, the injury having 
occurred in July after the period when the apple was able to heal perfect scars. Photographed 
on Dtcember 18 

83, Jonathan apple with tussock-moth scar, showing warting in the mature scar. Photo- 
graphed on October 31 

84, Apple showing a tussock-flioth scar (below), and warting produced on a scab spot (above). 
Photographed on September i 

85, Baldwin apples showing palmer-worm work. The larva that caused the injury may be 
seen protruding its head from a webbed retreat. Photographed on June 25 



Bulletin 410 



Plate XXI 




Plate XXII 

INJURIES PRODUCED BY YPSOLOPHUS LIGULELLUS AND BY TMETOCEI<A OCELLANA 

86, Roxbury apple with two small holes made by a palmer worm, showing also some of the 
web which the larva invariably spins about the cavities it makes. Photographed on July 27 

87, Roxbury apple with five small holes tnade by one palmer worm. The crack showing at 
either side is the result of growth after the skin of the apple had become hardened. Photographed 
on July 21 

88, Roxbury apples showing scars produced by late feeding of the palmer worm. The apple 
on the right shows a large and imperfectly healed scar, while the one on tlie left has a deep 
cavity where a larva fed for a short time just prior to pupation. Photographed on August 12 

89, Pound Sweet apple showing the work of a bud-moth larva just beneath a leaf that was 
webbt'd to the side of the fruit. Photographed on September 15 

90, A slice from an apple showing where a bud-moth larva had drawn a leaf against the 
fruit and fed for a short time. Photographed on August 8 



Bulletin 410 



P'LATE XXII 




Plate XXIII 

INJURIES PRODUCED BY EULIA VELUTINANA 

91, The leaf-roller larva and ils work between two Genesee Flower apples. Photographed 
on July 28 

92, The moth spread, enlarged about four times 

93, Rhode Island Greening apple showing the work of a larva. Photographed on Septem- 
ber 21 

94, Baldwin apple showing the typical shallow, late-feeding work of the larva, in which 
little more than the skin of the fruit is eaten. Photographed on September 25 



Bulletin 410 





Plate XXIV 

INJURIES PRODUCED BY COLEOPHORA MALIVORELLA 

95, Case-bearers at work on young apples, showing the small round holes that the larvae 
make in the fruit. Photographed on June 9 

96, Twenty Ounce apples exhibiting typical work of the larvae. Some of the larger scars 
show a small, funnel-shaped depression at the center, indicating that growth had not com- 
pletely filled the feeding cavity. Photographed on August 30 

97, Twenty Ounce apple showing the life work of one larva. The larger scars were made 
while the apple was growing rapidly, while the smaller scars were made toward the end of the 
larval feeding period. The " pistol case " may be seen on the twig to which the larva moved 
for pupation. Photographed on August 30 



Bulletin 410 



P'LATE XXIV 




Plate XXV 

INJURIES PRODUCED BY COLEOPHORA MALIVORELLA AND BY COLEOPHORA FLETCHERELLA 

98, Mature scars on Detroit Red apple caused by Coleophora malivorella, showing that a 
splitting and enlargement of the wound has taken place around certain scars. Photographed on 
October 2 

99, Work of Coleophora malivorella on a crab apple, showing that some warting occurred on 
the scars. Photographed on September 27 

100, Slices from Baldwin and Twenty Ounce apples which exhibit all types of scars caused 
by Coleophora malivorella. . Photographed on September 3 

loi, Coleophora Hetcherella, showing the case-bearers at work and the feeding punctures 
they make. Slightly enlarged. Photographed on May 29 



Bulletin 410 



Plate XXV 




Plate XXVI 

INJURIES PRCDUCED BY HYPHANTRIA TEXTOR 

102, Alexander apple showing the work of webworms on the fruit, with web and excrement 
clinging to it. Photographed on July 29 

103, Yellow Transparent apple which was fed upon by webworms with the result that it 
shriveled and dried up. Photographed on August 2 

104, Alexander apples on a limb that was inclos;d in a webworm nest. The work of the 
larvae may be seen on the apples. Photographed on July 28 



RUI.I.ETIN 410 



P'LATE XXVI 




Plate XXVII 

INJURIES PRODUCED BY MARMARA POMONELLA AND BY CONOTRACHELUS NENUPHAR 

105, Baldwin apple showing a serpentine mine in the skin of the fruit, produced by 
Marmara pomonclla. Photographed en November lo 

io6, Baldwin apple showing a serpentine mine of Marmara pomonclla which was more or 
less coiled and formed a blotch. Photographed on November lo 

107, A Conotrachclus nenuphar curculio resting on a young apple beside a feeding 
puncture. Enlarged 2 14 times. Photographed on May 29 

108, A Conotracheliis nenuphar curculio resting on a young apple after having made a 
small feeding puncture, which may be seen just beneath. Enlarged 2V2 times. Photographed 
on May 29 

109, Two young apples showing crescents made by the female of Conotrachelns nciuiphar 
when laying eggs, and one fruit (at right) showing a typical round feeding puncture. Enlarged 2 
times. Photographed on May 29 

no, A Conotrachclus nenuphar cvjrculio making a feeding puncture in a large apple. 
Photographed on June 25 



Bulletin 410 



Plate XXVII 




Plate XXVIII 

INJURIES PRODUCED BY CONOTRACHELUS NENUPHAR 

111, Baldwin apples showing egg crescents made by curculios when feeding early in June. 
Two of the crescents show a white exudation issuing from the egg puncture, indicating that 
the young grubs are trying to feed. Photographed on June i8 

112, Apple in section, showing the burrow of a curculio larva leading from the egg 
puncture toward the core. This fruit was picked from the tree just before the photograph was 
made, on July 13 

113, Injuries on a Rhode Island Greening apple with which a female curculio was caged 
from June 29 to July 6. Photographed on July 21 

114, Twenty Ounce apple showing several egg-croscent scars. Some of these resemble 
case-bearer work, but the egg-puncture mark which is discernible on all but one scar indicates 
that the plum curculio made the wounds. Photographed on September 9 

115, Red Astrachan apple showing both the crescents made by the plum curculio, and the 
irregular, splitting scars resulting from punctures of Lygidea mendax. Photographed on July 8 



Bulletin' 410 



Plate XXVIII 




//J 



'^.^ 



Plate XXIX 

INJURIES PRODUCED BY CONOTRACHELUS NENUPHAR 

ii6, Curculio injury on two Roxbury apples, produced during the last few days of July 
and the first week of August. The fruits show feeding punctures as well as egg crescents. Sev- 
eral of the punctures are surrounded with brown rot. Photographed on August 8 

117, Slices from apples showing egg-crescent scars which are perfectly formed but some of 
which are much less distinct than are others. Photographed on November 29 

118, Northern Spy apple showing the irregular scars produced by Lygidea menda.r, which 
may be distinguished from the scars with uniform margins that usually result from curculio 
punctures. Photographed on September 15 

119, Jonathan apple showing curculio scars bulging out or warting beyond the normal 
surface of the fruit. Photographed on October 31 



Bulletin 410 



Plate XXIX 




Plate XXX 

INJURIES PUODUCED BY CONOTRACHELUS NENUPHAR AND ]!Y ANTHONOMUS 

OUADRIGIBBUS 

120, Rhode Island Greening apple on which curculio scars were enlarged by muscid flies, 
the flies feeding on the brown rot as it formed in the wounds. Photograjihed on August 22 

121, Rhode Island Greening apple (at left) and Maiden Blush apple (at right) cut in sec- 
tion to show the extent of the cavities formed where flies had enlarged the wounds made by 
Conotrachelus nenuphar. Photogra' bed on August 22 

122, An Antlionomns qjiadrigihbns curculio on the side of a young apple. Enlarged 2% 
times. Photographed on May 29 

123, A female of Anthonomus qiiadrigibhtis ovipositing in a young apple while a second 
beetle rests on the calyx above. Photographed on May 28 

124, Two Anthonomus qiiadrigibbus curculios resting on a j'oung apple after one has laid 
an egg. Photographed on I\Iay j8 

125, Baldwin fruits which were so severely injured by Anthonomus qiiadrigibbus lietween 
June 25 and June 30 that they dropped. Photographed on July 7 

126, Baldwin apple cut in section to show the egg and feeding cavities made by 
Anthonomus qiiadrigibbus. Photographed on July 5 



Bulletin 410 



Plate XXX 




Plate XXXI 

INJURIES PRODUCED BY ANTHONOMUS OUADRIGIBBUS 

127, Daldwin apples showing the scars produced by a pair of curcuHos which were caged on 
the fruit from June 16 to July 6. Natural size. Photographed on October 21 

128, Stark apples which recovered from egg punctures made by an apple curculio near the 
end of June. Photographed on September 5 

129, Bartlett pears showing the egg and feeding punctures produced by a pair of apple 
curculios in the first week of July. The punctures all became filled with a hard, granular 
substance during subsequent growth. Photographed on September 9 



Bulletin 410 



Plate XXXI 




1^9 



Plate XXXII 

INJURIES PRODUCED BY M ACRODACTYLUS SUBSPINOSUS 

130, Baldwin apples showing the deep, irregular wounds produced by feeding rose chafers. 
Photographed on July 3 

131, Baldwin and Tompkins King apples which show typical injuries caused by feed- 
ing rose chafers at the end of June. Photographed on July 3 

132, Apples injured by rose chafers and found to have developed brown rot. All of these 
fruits shriveled and fell from the tree within two or three weeks after the injury occurred. 
Photographed on July 14 



Bulletin" 410 



Plate XXXII 




Plate XXXIII 

INJURIES PRODUCED BY RHAGOLETIS POMONELLA 

133, A female apple-maggot fly in position for ovipositing in a crab apple. Photographed on 
September 5 

134, Maiden Blush apple showing several oviposition marks. Photographed on August 23 

135, Maiden Blush apjile cut in section to show the work of the maggots within, also 
(at right) the emergence holes of the mature maggots. Photographed on September 5 

136, Maiden Blush apple in section, showing two mature maggots in the brown-rot areas and 
also the tunnels made by other maggots in the flesh of the fruit. Photographed on October 31 



Bulletin 410 



Plate XXXIII 




/JJ 




JS4 




Plate XXXIV 

INJURIES PRODUCED BY RHAGOLETIS POMONELLA, THE BLACK ROT FUNGUS, AND SYNTO- 

MASPIS DRUPARUM 

137, Tompkins King apple showing the emergence holes of two apple maggots. One of 
these scars represents the extent to which brown rot developed during the four days following 
the exit of the maggot. Photographed on October 7 

138, Crab apples showing the small dimples caused by the ovipositor of the chalcis fly, 
Synloinaspis druparum. Photographed on August i 

139, Tompkins King apple showing the emergence holes of apple maggots and the develop- 
ment of brown rot at the surface about the exit holes. Photographed on November 29 

140, Baldwin apple showing num;rous oviposition marks made by the apple-maggot fly. 
Each puncture appears somewhat enlarged and is surrounded by a dark green color, a con- 
dition caused by the black rot fungus {Physalospora Cydoniae) and the New England fruit 
spot (Phoma po)ni), which were probably being introduced as an infection on the ovipositor of the 
fly. Pho4:ographed on October 28 

141, Crab apples infested with the apple maggot. The lower apples show the dark tunnels 
of the maggots, which may be seen through the skin of the fruit. The apjjles in section 
show the extent of the tunnels and the development of brown rot. Photographed on Septem- 
ber 21 

142, Crab apples cut in section to show the dark trails left by the ovipositor of the female of 
Syninmaspis druparum. These scars may be seen leading from the surface of the fruit to the 
seeds. Photographed on August i 



Bulletin 410 



Plate XXXIV 




Plate XXXV 

AMETASTEGIA GLABRATA, AND THE WARTING OF SCARS CAUSED BY VARIOUS INSECTS 

143, Section through an apple, showing the larva of Ametastegia glabrata in its hibernating 
cell. Photographed on October 28 

144, Tolman apple with russet scars caused by Lygidca mcndax, showing a slight warting 
of the scars. Photographed on September 18 

14s, Rhode Island Greening apples showing russet scars caused by Lygidea mendax. These 
apples underwent forced growth during August, causing a warting of the scars. Photographed on 
December 14 

146, Ben Davis apples showing unusual warting 01 the scars made by tussock-moth larvae. 
Photographed on December 4 



Bulletin 410 



PlATE XXXV 




Plate XXXVI 

MECHANICAL INJURIES, TIN PUNCTURES, AND CRACKING FRUIT 

147, Rhode Island Greening apple which was rubbed constantly by a limb just beneath, 
from the time it was an inch in diameter until picking time. Photographed on October 23 

148, Baldwin apple which during its develo/ment was blown frequently against a sharp 
stub. Photographed on September 25 

149, Rhode Island Greening apple which had small holes punched through the skin by a 
very sharp stub. Photographed on September 1 5 

150, Baldwin apple showing the russet surface developed due to its rubbing against a stub 
from the time it was one-half inch in diameter until it had grown to be one and one-half inches 
in diameter, when the obstruction was removed. Photographed on October 23 

151, Mature scars on a Rhode Island Greening anple, produced by puncturing the young 
fruit on June 25 with a No. o msect pin. Photographed on September 25 

152, Roxbviry apple showing large, deep cracks. Photographed on August 14 



Bulletin" 410 



Plate XXXVI 



t>*' ^ 




Plate XXXVII 

CRACKING FRUIT, AND LIME-SULFUR SPRAY INJURY 

153, Roxbury apple completely circumscribed by a large crack. Photographed on July 21 

154, Rhode Island Greening apples showing deep cracks which probably had their origin in 
the russ.'t scars caused by redbugs. Photographed on August 17 

155, Rhode Island Greening apple which developed large cracks over the surface, covered 
by the broad russet type of redbug scars. Photographed on August 30 

156, Baldwin apple which was drenched with commercial lime-sulfur at the time of the 
calyx spray. Photographed on September 9 

i57> Apples from one limb of a Baldwin tree which always bore fruit having a russet skin 
and developing large, deep cracks. Photographed on August 22 



Bulletin 410 



PtATE XXXVIT 




i^z 



Plate XXXVIII 

LIME-SULFUR SI'RAY INJURY, SUN-SCALD, AND FROST INJURY 

158, Tompkins King apple which was drenched with lime-sulfur spray (i to 40) at the 
time of the calyx spray, that being the last time the tree was sprayed. Photographed on 
August 1 4 

159, Sun-scald. Baldwin apple cut in section, the scalded tissue showing dark near the 
surface of the fruit. Photographed on August 16 

160, Rhode Island Greening apples covered with spray material, which show dark on one 
side as a result of sun-scald. I'hotographed on August 16 

161, Baldwin apple which developed sun-scald on August 5, as it appeared at picking time. 
The scalded tissue first turned brown, and then dried out and developed cracks as shown. 
Photographed on October 21 

162, Young apples showing scars which gave the first signs of frost injury following the 
frost of May 28. Photographed on June 18 



Bulletin 410 



P-LATE XXXVIII 




J60 




Plate XXXIX 

FROST INJURY 

163, Northern Spy apple showing severe frost injury. This was picked in an orchard 
where nearly all of^ the fruit was killed by frost. Photographed on August 26 

164, Genesee Flower apple showing a frost band about its circumference and one crack 
along the axis. Photographed on August 23 

165, Large frost bands on two Genesee Flower apples. Photographed on August 17 

166, Red Astrachan apples showing; prominent frost bands. Photographed on August 21 
167, Baldwin apples showing frost injury at the calyx end only. Photographed on August i 



Bulletin 410 



P-LATE XXXIX 




165 





j63 



166 



/64 




J67 




Plate XL 

FROST INJURY AND HAILSTONE INJURY 

1 68, Maiden Blush apple showing the frost band broken into segments, also a slight 
warting of the scars. Photographed on September 7 

169, Rhode Island Greening apple with scars that represent severe freezing of the yoitng 
fruit. Photographed on September g 

170, Golden Russet apples showing cracks and excess russeting due to frost injury. 
Photographed on August i 

171, Northern Spy apples broadly marked with russet on the basal half, due to frost 
injury. Photographed on August i 

172, Sections of apples taken immediately beneath hailstone spots such as are shown in 
Plate XLI, 173. Photographed on August -i 



Bulletin' 410 



P'LATE XL 



f 




Plate XLI 
hailstone injury 

173, A Baldwin apple, injured by hailstones on July 20, as it appeared on August 4 

174, A Baldwin apple which was injured by a large angular hailstone on July 20, as it 
appeared on August 4 

175, A Baldwin apple which was badly injured by a hailstone on July 20, showing the 
stage of recovery that it had reached on August 17 

176, An apple showing four hailstone injuries that were inflicted early in July, and one 
small fruit-worm scar (in center) which very much resembles them. Photographed on August 23 

177, Crab apples showing several hailstone scars. Photographed on August 17 

178, Baldwin apples that received several hailstone pecks, shown to be recovering when 
photographed on August 17 



Bulletin 410 



Plate XLI 




Plate XLII 
injuries produced by ai'l-'le scai! and stiffen 

179, Scab spots on Rhode Island Greening apples, showing the papery edge which 
surrounds the dark central snot. Photographed on July 20 

180, Excessive scab development on one side of a Rhode Island Greening apple. The scab 
caused the skin to dry out and harden, with the result that a large crack developed. Photo- 
graphed on July 20 

181, Rhode Island Greening apple showing the spots caused by late scab infection. Photo- 
graphed on September i 5 

182, Baldwin apple in section, showing dark discolorations in the flesh where stippen has 
developed. Photographed on August 22 



Bulletin 410 



Plate XLII 





JS2 



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